Highly Flexible Transistor Threads for All-Thread Based Integrated

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Highly Flexible Transistor Threads for All-Thread Based Integrated Circuits and Multiplexed Diagnostics. Rachel E Owyeung, Trupti Terse-Thakoor, Hojatollah Rezaei Nejad, Matthew J Panzer, and Sameer R. Sonkusale ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.9b09522 • Publication Date (Web): 05 Aug 2019 Downloaded from pubs.acs.org on August 6, 2019

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ACS Applied Materials & Interfaces

Highly Flexible Transistor Threads for All-Thread Based Integrated Circuits and Multiplexed Diagnostics. Rachel E. Owyeung1,3, Trupti Terse-Thakoor2,3, Hojatollah Rezaei Nejad2,3, Matthew J. Panzer1, Sameer R. Sonkusale2,3,*

1Department

of Chemical and Biological Engineering, Tufts University

Science and Technology Center, 4 Colby Street, Medford MA 02155, USA

2Department

of Electrical and Computer Engineering, Tufts University

Halligan Hall, 161 College Ave, Medford MA 02155, USA

3Nano

Lab, Tufts University

Advanced Technology Laboratory, 200 Boston Ave. Suite 2600, Medford MA 02155, USA

ACS Paragon Plus Environment

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KEYWORDS: Ionogel gated transistors, thread diagnostics, thread-based transistors, multiplexed sensors, flexible bioelectronics, wearable devices

ABSTRACT:

Physically intimate, real-time monitoring of human biomarkers is becoming increasingly important to modern medicine and patient wellness. Such monitoring is possible due to advances in soft and flexible materials, devices and bioelectronics systems. Compared to other flexible platforms, multi-filament textile fibers or threads offer superior flexibility, material diversity, and simple ambient processing to realize a wide range of flexible devices such as sensors, electronics, and microfluidics. In this paper, we realize unique flexible transistors on threads and interconnect them to realize logic gates and smallscale integrated circuits. Compared to prior textile-based transistors, the proposed thread-based transistors (TBTs) are realized with a readily shaped, colloidally dispersed gel

consisting

of

silica

nanoparticles

and

1-ethyl-3-methylimidazolium


2

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bis(trifluoromethylsulfonyl)imide (EMI TFSI) ionic liquid for all-around electrolyte gating of a carbon nanotube (CNT) semiconducting network assembled on the thread. We interconnect TBTs with thread-based electrochemical sensors (TBEs) to realize an allthread based multiplexed diagnostic device. All-thread based platforms are thin, highly flexible and conformal, allowing them to be worn directly on the skin without any polymeric substrate, or sutured transdermally using a needle.

1. Introduction Modern medicine emphasizes real-time monitoring of patient health using a suite of smart sensors and on-demand delivery of treatments (e.g. drugs) at the point of care.1–3 This has the potential to improve health outcomes through early onset detection of a disease and through effective management of the treatment personalized to each individual.3,4 With an increasing number of sensors, there is a need to integrate electronics for multiplexed readout and amplification. Conventional bulk silicon-based microelectronics and sensors are ill-suited for this task because of the modulus mismatch


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between the silicon-based devices, which are rigid and inflexible, and the biological medium they will interface with, which is inherently soft and flexible. Technological advances in soft and flexible materials and processing can provide a potential solution. In fact, there has been record growth in the development of flexible sensors, electronics, microfluidics and integrated systems that can be worn or implanted.5–12 For example, the work by Rogers and coworkers utilized the strategic patterning of metals and inorganic semiconductors into “wavy” structures, making them flexible and stretchable.6,13–15 Other strategies involve the use of intrinsically stretchable materials such as conducting polymers leading to a growing trend in the area of “soft” organic electronics.9,11,16–19 These approaches have resulted in BioFlex devices and systems that conform and stretch with underlying tissue such as skin, heart or brain for recording or modulating them with great success. Recently, multi-filament textile fibers or threads have emerged as a platform for diagnostic devices and tissue engineering.20,21 Notably, threads have a tunable modulus to match a desired biological tissue,21,22 can be minimally invasive (as exemplified by sutures), and can provide a natural interface with three-dimensional tissues and organs.20


4

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Compared to other flexible platforms based on thinned silicon or polymers (e.g. polyimide, parylene, PDMS), threads offer superior flexibility, material diversity, and simple ambient processing to realize a wide range of flexible devices such as sensors, electronics, and microfluidics. Our group has demonstrated a tool kit of thread-based devices such as temperature sensors,20 strain sensors,23,24 drug delivery systems,25 electrochemical sensors for glucose and pH,26–28 and optical sensors for volatiles.29 In this investigation, we expand this toolkit and present the design and fabrication of thread-based transistors (TBTs) and an all-thread integrated circuit based on TBTs. We also show how these TBTs can be interconnected to chemical sensing threads to realize an all-thread multiplexed diagnostic platform. The overall platform is extremely thin, soft and flexible for intimate integration with biological tissues such as skin without affecting their natural function. Previous reports of thread-like transistor geometries date back to 200330 realized either as organic electrochemical transistors (OECTs) or organic field effect transistors (OFETs).19,31–38 Mattana et al. demonstrated both OFETs and OECTs on thread, using a parylene-C coating to make the thread a uniform surface prior to pentacene deposition.19 Hamedi et al. demonstrated OFETs on Au sputter coated fibers using an ionic liquid and


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poly(ionic liquid) electrolyte gate.32 Recently, Heo et al. showed CMOS circuits on wirebased substrates using a reel-process to align carbon nanotubes (CNTs) for better device performance.38 While there have been several dozen reports on thread-like transistor devices, these are either based on wire-type substrates or polymer coatings to ensure surface smoothness and may involve cleanroom processes to deposit metals and oxides. These approaches often do not retain some advantageous features of the original threads, such as their flexibility and chemical tunability. In this report, we present highly flexible thread-based devices realized using cleanroom-free fabrication processes such as drop casting, drying, and stitching in an ambient environment. More specifically, we describe unique thread-based transistors (TBTs) realized using electrolyte gating of semiconducting carbon nanotube networks on linen threads, with gold wire drain/source electrodes. The electrolyte consists of a colloidally dispersed silica nanoparticlesupported ionic liquid gel (an ionogel, also known as an ion gel), which allows for allaround electrostatic gating of the CNT transistor. Further, we demonstrate a first of its kind integration of the TBTs with thread-based electrochemical sensors (TBEs) to facilitate multiplexed detection in an all-thread based multiplexed diagnostic platform


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(conceptual schematic shown in Figure 1). This conceptual schematic shows a threadbased integrated platform consisting of three different functions all realized using threads: sampling, sensing and electronic switching. Sampling is enabled by bare wicking threads (either standalone or as a fabric) that draws sampling fluid to the TBEs, which then sense target analytes. Individual TBEs are selected electronically for readout using TBTs serving as an electronic switch configured collectively as a multiplexer. In this study, we demonstrate all-thread multiplexed sensing of ammonium and sodium ions, which are important biomarkers of cardiovascular, kidney, and liver health.39–43 Figure 1(b) shows how compatible these flexible threads are as a platform for biologically integrated electronics. Here, we have highlighted the threads for better visualization, as they are almost imperceptible due to their thinness and flexibility. Thread-based platforms do not require a supporting polymeric substrate and they can be directly integrated directly on skin or embedded into skin as sutures or implants. The absence of a supporting substrate enables the underlying tissue to interact with its environment and breathe naturally to receive oxygen and other micronutrients.44 2. Results and Discussion


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2.1. Device fabrication The most critical challenge in realizing a 3D transistor on fibrous substrates such as threads is obtaining a uniform 3D deposition of the gate dielectric. Classical materials for gate dielectrics are typically solid-state oxides or polymers, which may not provide reliable performance for 3D fibrous structures such as threads, especially when subjected to flexing or stretching. An electrolyte gate dielectric, such as that provided by an ionic liquid, relies on electrostatic double layer (EDL) capacitance and can be resilient under stretching or flexing.45 An ionogel employs a solid scaffold to support an ionic liquid, which was first used for gating an OFET by Frisbie and co-workers.46 Like many scaffold supported electrolyte gates, the use of an ionogel provides large specific capacitance for higher ON currents and lower switching voltages,45,47 but additionally offers low volatility and a large electrochemical stability window. Use of electrolyte gating for transistor operation also eliminates the problem of an uneven conventional insulating dielectric coating. For ionogel-gated transistors, the thickness of the gate dielectric material does not influence its capacitance.48 Rather, it is the formation of EDL capacitance at the interface of the electrolyte and metal/semiconductor that is responsible, though it should


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be noted that electrochemical doping can occur at higher VG, especially for polymer semiconductors like P3HT.47,49–51 Common methods of creating an ionogel gate dielectric, however, rely on the synthesis of triblock copolymers or a need for additional UV or thermal curing (as is the case for chemically cross-linked gels), which would make fabrication on a thread difficult. Nanocomposite ionogels formed via the dispersion of fumed silica nanoparticles in ionic liquids were studied previously by Ueno et al.52–54 While these materials have been extensively studied over the last decade, they have not yet been incorporated into many application-based studies, other than a report describing a color display.55 Here, we show for the first time the successful use of these colloidal silica-based ionogels for electrolytegated thread based transistors. The primary advantage of these colloidal gels is their shear thinning nature, which allows for easy application to a thread post-gelation. This could be either through dip coating or by swabbing the gel onto the thread at high shear rates. The shear applied through these methods renders the gel more liquid-like to apply, which then regains its solid-like properties after placement on the device. 2.1.1. Gel fabrication and characterization


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In this paper, silica nanoparticle-based colloidal ionogels are utilized for electrolytegated transistors for the first time. Gelation occurs upon mixing 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI), the ionic liquid (IL), and a relatively low concentration of hydrophobic silica nanoparticles having an octylsilyl surface modification. Due to attractive van der Waals interactions, these nanoparticles form an interconnected network within the IL medium, resulting in a gel. A photograph of the as-formed gel is shown in Figure 2(a) and schematically shown in Figure 2(b) with the EMI TFSI chemical structure as its inset. EMI TFSI was selected as it is well studied regarding ionogel gated transistors. However, more biofriendly ionic liquids or deep eutectic solvents could theoretically be used here instead (see Figure S1).56–58 For this application we used a 5 wt.% silica concentration to form the ionogel (i.e. 95 wt.% IL). The high concentration of IL allows for high ionic conductivity and a low shear modulus, while offering the advantages of a solid-like composite in the absence of shear.52,54 Upon mixing, gelation occurs, and the resulting viscoelastic gels are compliant and easily integrated onto the electrolyte-gated TBTs. The ionogels are expected to be stable in upwards of 50% relative humidity, since the nanoparticles have hydrophobic octylsilyl


10

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surface modifications and EMI TFSI itself is hydrophobic. This endows the gel with stability in a humid environment. We have seen that gels that have been left out in the laboratory for over 6 months visually look unchanged and the transistor performance using these aged gels has not diminished versus transistors that have been fabricated with freshly prepared gels. AC impedance measurements were performed to examine the ionogel electrical properties. For this, the gel was sandwiched between two tin-doped indium oxide (ITO) coated glass slides separated by a poly(tetrafluoroethylene) spacer. Specific capacitance values were calculated by Equation (1): 𝐶 = (2𝜋𝑓𝐴|𝑍"|)

―1

(1)

where 𝑓 is frequency, A is the cross-sectional gel area, and 𝑍" is the imaginary component of impedance. Specific capacitance versus frequency is shown in Figure 2(c) in the frequency region where the magnitude of impedance changes with frequency, and hence is dominated by the capacitive behavior of the gel.45,59 At lower frequencies (1 Hz), capacitance of the gel reaches nearly 18 μF/cm2. This is comparable to similar reports


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using EMI TFSI supported by different scaffolds, as the specific capacitance should be dominated by the IL electrolyte medium itself.46,59 2.1.2. Transistor fabrication Two different types of p-type TBTs were fabricated, one using CNTs as the semiconducting channel material and a second using the organic semiconductor P3HT (regioregular poly(3-hexylthiophene)). This demonstrates the versatility of the ionogel gate dielectric and fabrication scheme for usage in transistors of different semiconductor types. As this is the first report to our knowledge utilizing this type of ionogel for transistors, planar analogs were also fabricated and are described in the Supporting information (see Figure S2). The fabrication process, along with device images, is shown in Figure 3. For TBTs, the transistors are fabricated on linen sutures. Source and drain contacts were made by physically knotting Au wires around a bare linen thread (Figure 3(b)). Notably, this is different from previous reports of thread-like transistors, where the electrodes were deposited via sputtering.32 This method of knotting the source and drain electrodes to the linen thread allows us to maintain the ability to modify the thread further, for example, to coat it with a sensing material (see Figure 1(b)) or to retain the flexibility


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and mechanical properties of the native thread while maintaining a stable connection. In this realization of FETs, the source and drain contacts are the main cost. We are actively exploring alternative connections to move towards more cost-effective interconnects such as using goldcoated nickel or copper wires. The semiconductor solution is drop cast onto the active channel area (Figure 3(c)) and then the ionogel is pasted on top (Figure 3(d)), enabled by high shear application of the shear thinning gel. Finally, another Au wire serves as the gate electrode, and is placed on top of the gel (Figure 3(e)). A schematic illustration of the double layer formation surrounding the 3D channel is shown in Figure 3(f). This image (not to scale) shows the expected all-around electrostatic gating, whereby the active channel W/L ratio is increased without needing to create a smaller gap between the source and drain electrodes. The length is consistent at 0.5 mm between the source and drain electrodes, while the width is the circumference of the thread substrate, resulting in a W/L ratio around 2. A larger W/L ratio could be achieved with a thicker thread substrate, if desired. 2.2. Transistor performance


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Transfer and output characteristics are shown for a CNT thread transistor in Figures 4(a) and 4(b), respectively, and for a P3HT thread transistor in Figures 4(c) and 4(d), respectively. Hysteresis is notable, although hysteresis is common and intrinsic to many electrolyte-gated FETs. This is largely due to the relatively slow movement of ions versus electrons and the large capacitance value of the two EDLs in series. Hysteresis for these devices can be improved by reducing the gate voltage sweep rate60 and by increasing the relative area of the gate electrode relative to the active channel area by several orders of magnitude.61 Regardless, TBT performance is comparable to that of the planar devices (see Figure S2). CNT TBT devices displayed an operating voltage around 0 to -2.5 V, effective linear mobilities of approximately 3.6 ± 3.5 cm2V-1s-1, ON/OFF ratios of 102, and threshold voltages around -0.88 ± 0.27 V, averaged over seven different transistors. The effective linear mobility differences between samples is notable, which can be explained by the dependence of the CNT orientation upon drop casting. This could be improved by alignment of the CNTs upon employing a dip-coating method of fabrication as shown previously.38 Regardless, these values are similar to existing reports of CNT transistors created on a wire substrate.38 For P3HT TBTs, hysteresis in the transfer characteristic is


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more notable. It has been shown that P3HT can be electrochemically doped by ions of the gel electrolyte, and slow diffusion out of these ions out of semiconducting polymer could explain a more notable hysteresis, especially if the P3HT is plasticized due to the absorption of some moisture under ambient conditions.47,49–51 Some of the discussed strategies to minimize hysteresis are shown in the Supporting Information (Figure S3). The P3HT TBT operating voltage was 0 to -2.5 V with effective linear mobilities of 3.2 ± 1.7 cm2V-1s-1, ON/OFF ratios of 102, and threshold voltages around -1.3 ± 0.1 V, averaged across seven different samples. Effective semiconductor mobilities are larger compared to those observed in conventional OFETs, although this has been noted before for electrolyte-gated transistors.46,62 This is attributed to the induction of an extremely large charge density facilitated by the high EDL capacitance values.48 Since one of the goals of our TBT fabrication approach was to ensure flexibility of the thread substrate even after the device was completed, we measured transfer curves of TBTs at different bending radii. Figure 5(a) shows the transfer curve of a CNT TBT at different bending radii and Figure 5(b) shows the threshold voltage extracted from the transfer curves. The results showed a slight increase in OFF current upon each subsequent measurement, but the


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threshold voltage remained relatively unchanged and within the standard deviation, thus indicating that the transistors can withstand mechanical deformation. More information on the bending test setup and the results for the P3HT TBTs can be found in the supporting information (Figure S6). 2.3. Simple logic circuits enabled by CNT TBTs We demonstrate three distinct logic circuits, namely NAND, and NOR, and NOT (or inverter) using only p-type CNT TBTs. NAND, NOR, and NOT gates are chosen as universal gates for demonstration since any digital logic can be made with different combinations of these logic gates.63 The logic table, electrical schematic, and electrical measurement signals of each logic circuit can be seen in Figure 6(a-c) for NAND, NOR, and NOT, respectively. The electrical measurements for NAND and NOR are continued further to demonstrate the complete logic table and can be found in the Supporting information (Figure S7). Notably, in place of resistive loads, we use another CNT TBT with a higher OFF current than our typical CNT TBTs. Non-optimal drop casting of CNT solution can achieve higher OFF current during fabrication, which increased the OFF current by an order of magnitude. Thus, this element acts more like a variable resistor,


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rather than a transistor, which we can use to our advantage to create fully p-type TBT logic circuits. Square pulses of 0 V to 2.5 V via function generator were applied as an input, and an oscilloscope was used to record the input signals and resulting output of the respective circuit. Compared to the rail-to-rail input, the resulting output swing is not full scale. This is to be expected because of the use of resistive load instead of an n-type transistor, resulting in IR drop across the resistor for one of the two logic outputs. This is further exacerbated by the relatively lower ON/OFF ratio of the TBTs versus the CMOS equivalent. Regardless, there is still a clear difference between the high and low binary states for each logic circuit, indicating that these can be used for digital logic and simple logic-based integrated circuits. 2.4.1. Small-scale thread-based integrated circuit: MUX demonstration TBTs provide a necessary building block for the development of all-thread based biologically integrated electronics. For proof of concept, we sought to combine TBTs with thread-based electrochemical sensors (TBEs) to realize an integrated transistor and sensor thread-based diagnostic platform. Towards this goal, we first demonstrate a smallscale integrated circuit, namely a multiplexer (MUX) that will be integrated with TBE


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sensor array. The MUX highlights the use of transistors as switches for signal selection. MUXs are common in electronics, especially in memories or arrays to provide switching and reduce the input/output interconnect and wiring requirement. For example, a 1:2N MUX will facilitate connection to one of the 2N sensors with just N-bit word lines to turn on a TBT switch connecting the given sensor line read to the output. In combination with logic gates demonstrated earlier, MUX can be used to implement complex digital systems in an all-thread based realization.64 2.4.2. Integration of TBT MUX with TBEs for all-thread based multiplexed diagnostics We construct a model platform for integration of both TBEs and TBTs, which can be used to realize all-thread based diagnostics. The TBT 3:1 MUX is created using CNT TBTs. It connects each of the three CNT TBTs in a MUX to one of the potentiometric working electrodes (WEs) that serves as the TBEs as shown schematically in Figure 7(a). A separate thread-based reference electrode (RE) is connected to ground. An electrolyte solution is drop cast on the analyte area for detection by the WE sensors. In actual application, one can sample the analyte directly using thread based microfluidics as shown in Figure 1 and exemplified in our prior work.20 We chose sodium and ammonium


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ion selective sensors due to their biological relevance, in order to access key biomarkers of cardiovascular health, liver, and kidney function in biological fluids, such as sweat or blood serum.39,42 These WEs achieve selectivity due to a standard dip coating of an ionselective polymeric membrane65 based on the nonactin ionophore for either ammonium or sodium.39,42 The open circuit potential (OCP) of the WEs changes with respect to the RE yielding a direct correlation to the concentration of ammonium or sodium ions. We discuss sensitivity and selectivity of these WEs in the Supporting Information (Figure S8). In our integrated platform here, WEs provide the input signals that are read through to a single output by controlling which TBTs are turned ON or OFF. We first validate the CNT TBT as a switch by turning the TBT in series with a given WE ON by applying a negative gate voltage. Figures 7(b) and 7(c) show the TBT in series with a sodium ion WE and an ammonium ion WE, respectively, during calibration of the respective WE sensor (the source electrode of each transistor is electronically connected to the WE). The grey points represent the raw data, with a smoothed curve in blue to correct for transient fluctuations that occurred during the measurements due to movement or line interference. These tests demonstrate the successful functioning of the TBT as a


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switch in a MUX configuration, validated by reporting an expected potential from the chosen WE. These results also show that the output signal is not changed significantly upon introduction of the transistor in series, indicating that the loading due to any leakage current is negligible. Thus, TBTs can be used for switching in a MUX design, among other logic gates. Also, it should be noted that the negative potential readings shown for the sodium ion sensor in series with the CNT TBT could be due to slight leakage of the TBT (high OFF current). To support these thread-based transistors as multiplexers, we extended the demonstration to show three separate WE and transistor pairs to sense biomarkers (ammonium or sodium ions) at discrete locations. The idea here is to selectively switch between the desired biomarker information at a discrete location and yield a single output through turning the corresponding transistor ON or OFF. An electrical schematic is shown in Figure 7(d). Turning on a specific transistor should allow current to flow through that given channel and the WE signal to be read at the MUX output. Figure 7(e) illustrates this selection of which signal is sent to the output. Each WE was selected for at least 60 seconds before its corresponding transistor is turned off and the next transistor is turned


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on. Figure 7(f) examines direct output of each of the WEs through the potentiostat. There is a slight offset for each WE when comparing to the MUX output from Figure 7(e), but this offset is consistent between each WE. The results show that while the MUX configuration does alter the output voltage signal slightly, it is of similar magnitude and can be accounted for during measurements by a calibration step. This demonstration suggests a way to selectively readout a desired sensor signal from an array by connecting to a single output channel. While a modest 3:1 multiplexing was demonstrated, one could scale this MUX to address the connectivity bottleneck resulting from a need to monitor many different biologically relevant compounds or the need to monitor these compounds at different target locations using multiple sensors with a single readout electronic system. 3. Conclusion We have demonstrated the successful fabrication and operation of colloidal silicasupported ionogel gated transistors on linen threads using P3HT and CNT semiconductors. These p-type thread-based transistors were used as a switch, multiplexer (MUX) and simple logic gates namely NAND, NOR, and NOT. For the first time, these thread-based transistors have also been integrated with thread-based


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electrochemical sensors and multiplexed sensing has been employed to showcase these transistors as effective, thin, and flexible building blocks for readout from a sensor array in an all-thread based diagnostic platform. These results are a preliminary step toward more advanced sensors and electronics for biomonitoring in transdermal applications, in the form of smart sutures and wearable technology, which can be validated in animal models in future work. 4. Experimental Section

Ionogel synthesis: Silica nanoparticles (Aerosil R 805, Evonik Industries) are dried inside a vacuum oven above 80 ̊C for at least 24 hours before use. The ionogel is prepared by combining 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI) (EMD Chemicals Inc.) and silica nanoparticles in the ratio of 5 wt.% nanoparticles/95 wt.% EMI TFSI. The solution is agitated using a vortex mixer for 5 minutes or until fully homogeneous.

TBT Transistor assembly: Au wires (0.1 mm dia, 99.95%, Alfa Aesar, USA) are attached on both ends of a twisted linen nonabsorbable suture (Covidien Medtronic, USA) for source and drain (S/D) contacts. For P3HT TBTs, a 15 mg/mL solution of regioregular,


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electronic

grade

Poly(3-hexylthiophene-2,5-diyl)

(Rieke

Metals,

USA)

in

1,2-

dichlorobenzene (anhydrous 99%) is drop cast between the S/D electrodes. For CNT TBTs, >99.9% semiconducting SWNTs (IsoNanotubes-S, Nanointegris Technologies Inc., Canada) is drop cast from a 0.01 mg/mL solution in toluene between the S/D electrodes. After drying, the ionogel is applied on top of the semiconductor-coated thread between the source and drain electrodes. Finally, a third Au wire is laid on top of the ionogel to serve as the gate electrode. Transistor assembly information for the planar transistors can be found in the Supporting Information.

Working electrode sensors for TBEs: Polyester threads were used as substrates for the TBE WE and REs. The threads were first air plasma treated, then coated with either C200 carbon resistive ink (Applied Ink Solution, USA) for WEs or AGCL-675 silver/silver chloride ink (Applied Ink Solution, USA) for the RE. Sodium and ammonium ion WEs were further modified by coating with nonactin sodium ionophore X or ammonium ionophore I doped polyvinyl chloride membrane solution, for sodium and ammonium WEs, respectively (Sigma Aldrich, USA). Each WE was calibrated by soaking in a 1 mM aqueous solution containing the given ion (NaCl for sodium and NH4Cl for ammonium)


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for at least 30 min. After, each WE was tested in 3 different concentrations, up to 100 mM (1 mM, 10 mM, 100 mM) of the respective solution. Potentiometry was conducted using a CH Instruments 600E Electrochemical Analyzer (CH Instruments, Inc.).

Electrical measurements: For all transistors, devices were tested using an Agilent 4156A Semiconductor Analyzer at room temperature and atmospheric pressure in ambient conditions. For ionogel characterization, the gel was sandwiched between two tin-doped indium oxide (ITO) coated glass slides (Thin Film Devices, Inc.) separated by a poly(tetrafluoroethylene) spacer, resulting in an ionogel thickness of 0.16 cm and crosssectional area of 0.32 cm2. AC impedance spectra were measured using a VersaSTAT 3 Potentiostat with a built-in frequency response analyzer (Princeton Applied Research). For logic gates, VDD and Vleak were driven by DC Power Supply HY3005-3 (RSR Electronics, Inc. USA). Square wave pulses of 0 V to 2.5 V were supplied to inputs A and B via AFG 3022B function generator (Tektronix, Inc. USA). Input and output signals were recorded via DS1204B Digital Oscilloscope (RIGOL Technologies USA Inc. USA). For MUX data, the respective TBT channel was turned ON at -1 V with the other channels


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held at 0 V using sourcemeters (Keithley 2400 or 6230). Readout was achieved using CH Instruments 600E electrochemical analyzer.

Figure 1. (a) Schematic of a thread-based integrated transistor system for advanced sensing of biologically relevant ions. The sample from wound tissue is brought to the sensor area via a sampling thread that wicks the liquid up through the tissue while simultaneously suturing the wound site. Threads are used as a substrate for both the sensors and transistors for flexibility and softness resembling underlying skin and bring the electronic signal to the microcontroller (μC). The insets show a close-up of the multiplexed sensing architecture used. (b) The thread-based integrated transistor system sutured into chicken skin. The threads sutured into the chicken skin as a microfluidic


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sampler are highlighted for better visualization. This demonstrates the seamless biointegration of threads as a bioelectronics substrate.

Figure 2. (a) Optical image of the formed colloidal gel in an inverted glass vial. (b) Schematic illustration of the ionogel formed by colloidal interactions between silica nanoparticles (shown in blue) within the ionic liquid, EMI TFSI (shown in green). EMI TFSI’s chemical structure can be seen in the inset. (c) Capacitance versus frequency data shows the high capacitance levels achievable by using ionogel gating due to the formation of electrostatic double layers.


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Figure 3. Fabrication scheme of the thread-based transistors (TBTs). The initial linen thread (a) is knotted with source/drain Au wire contacts (b). Then, the active channel semiconductor (P3HT or CNTs) is drop cast onto the thread (c). The ionogel is swabbed on top of the area to form the gate layer (d). Finally, another Au wire serves as the gate electrode (e). (f) A schematic illustration of the ionogel-gated thread transistor viewed looking down the axis of the thread (not to scale) highlights the TBT geometry with the ionogel gate dielectric enabling all-around electrostatic gating, thus increasing active channel dimensions without the need to form a smaller gap between source and drain electrodes.


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Figure 4. (a) Transfer and (b) output characteristics of a CNT TBT device. (c) Transfer and (d) output characteristics of a P3HT TBT device.


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Figure 5. (a) Transfer curve of a CNT TBT at different bending radii. (b) Threshold voltage values extracted from the transfer curves measured at different bending radii.


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Figure 6. Logic table, electrical schematic, and electrical measurements of different logic gates a) NAND b) NOR and c) NOT. Curves represent the two logic gate inputs, A and B, and the output from the circuit, Y.

Figure 7. A setup of the multiplexer architecture is shown (a) with three working electrodes (WEs), each with a TBT in series. (b) Validation of the transistor as a switch using a sodium ion sensor in series with a CNT TBT. Unmodified OCP with TBT in series and ON. Negative potential could be due to slight leakage of TBT. (c) Validation of the transistor as a switch using an ammonium sensor in series with CNT TBT. The grey represents the raw data, with the smoothed curve in blue to correct for transient fluctuations occurring during the measurement. A schematic for the MUX device setup is


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shown in (d). (e) Demonstration of the MUX turn on of each different channel to read out corresponding WE signals. (f) Direct output of each WE read by the potentiostat shows a slight offset between the MUX readout and the direct output of the WEs, but this offset is consistent between the devices.

ASSOCIATED CONTENT

Supporting Information. Transfer and output curves of a CNT DES TBT, Transfer and output curves of the planar device analogs of the P3HT and CNT transistors, experimental methods for the planar analogs, exploration of hysteresis-reducing strategies, SEM images of the linen thread substrate, Raman Spectroscopy of the CNT deposited on the linen suture, bending test setup information and results from bending tests of P3HT TBT, Electrical measurements of NAND and NOR logic gates, calibration curves and selectivity information of the sodium and ammonium ion sensors, and comparison of MUX output from WE1 with the direct output of WE1 are included. The following files are available free of

charge.

Supporting information (docx)


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AUTHOR INFORMATION

Corresponding Author *E-mail: [email protected]

Author Contributions The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.

Notes

The authors declare no competing financial interest

Funding Sources

R.E.O. acknowledges support by NSF IGERT under grant number DGE-1144591. S.S. and T.T. acknowledges partial support from the Center for Applied Brain and Cognitive Sciences (CABCS), a U.S. Army Natick Soldier Research, Development and Engineering Center under Cooperative Agreement W911QY-15-2-0001. S.S and H.R.N


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also acknowledges partial support of the Office of Naval Research (ONR) grant N001416-1-2550. ACKNOWLEDGMENT Aerosil R 805 nanoparticles were generously provided by Evonik Industries and linen sutures were generously provided by Covidien Medtronic.

REFERENCES (1)

Mostafalu, P.; Tamayol, A.; Rahimi, R.; Ochoa, M.; Khalilpour, A.; Kiaee, G.; Yazdi, I. K.; Bagherifard, S.; Dokmeci, M. R.; Ziaie, B.; Sonkusale, S. R.; Khademhosseini, A. Smart Bandage for Monitoring and Treatment of Chronic Wounds. Small 2018,

14 (33), 1703509.

(2)

Martinez, A. W.; Phillips, S. T.; Whitesides, G. M.; Carrilho, E. Diagnostics for the Developing World: Microfluidic Paper-Based Analytical Devices. Anal. Chem. 2010,

82 (1), 3–10.

(3)

Gubala, V.; Harris, L. F.; Ricco, A. J.; Tan, M. X.; Williams, D. E. Point of Care Diagnostics: Status and Future. Anal. Chem 2012, 84, 487–515.


33


(4)

Page 34 of 55

Wang, J. Electrochemical Biosensors: Towards Point-of-Care Cancer Diagnostics.

Biosens. Bioelectron. 2006, 21, 1887–1892.

(5)

Gao, W.; Ota, H.; Kiriya, D.; Takei, K.; Javey, A. Flexible Electronics toward Wearable Sensing. 2009.

(6)

Park, S. Il; Brenner, D. S.; Shin, G.; Morgan, C. D.; Copits, B. A.; Chung, H. U.; Pullen, M. Y.; Noh, K. N.; Davidson, S.; Oh, S. J.; Yoon, S.; Jang, K.; Samineni, V. K.; Norman, M.; Grajales-Reyes, J. G.; Vogt, S. K.; Sundaram, S. S.; Wilson, K. M.; Ha, J. S.; Xu, R.; Pan, T.; Kim, T.; Huang, Y.; Montana, M. C.; Golden, J. P.; Bruchas, M. R.; Gereau, R. W. IV; Rogers, J. A. Soft, Stretchable, Fully Implantable Miniaturized Optoelectronic Systems for Wireless Optogenetics. Nat. Biotechnol. 2015, 33 (12), 1280–1286.

(7)

Spyropoulos, G. D.; Gelinas, J. N.; Khodagholy, D. Internal Ion-Gated Organic Electrochemical Transistor: A Building Block for Integrated Bioelectronics. Sci. Adv. 2019, 5 (2), eaau7378.

(8)

Gutruf, P.; Rogers, J. A. Implantable, Wireless Device Platforms for Neuroscience


34

Page 35 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Research. Curr. Opin. Neurobiol. 2017, 50, 42–49.

(9)

X Xu, J.; Wang, S.; Wang, G.-J. N.; Zhu, C.; Luo, S.; Jin, L.; Gu, X.; Chen, S.; Feig, V. R.; To, J. W. F.; Rondeau-Gagne, S.; Park, J.; Schroeder, B. C.; Lu, C.; Oh, J. Y.; Wang, Y.; Kim, Y.; Yan, H.; Sinclair, R.; Zhou, D.; Xue, G.; Murmann, B.; Linder, C.; Cai, W.; Tok, J. B.-H.; Chung, J. W.; Bao, Z. Highly Stretchable Polymer Semiconductor Films through the Nanoconfinement Effect. Science 2017, 355 (6320), 59–64.

(10) Bao, Z.; Chen, X. Flexible and Stretchable Devices. Adv. Mater. 2016.

(11) Someya, T.; Bao, Z.; Malliaras, G. G. The Rise of Plastic Bioelectronics. Nature 2016, 540 (7633), 379–385.

(12) Chortos, A.; Bao, Z. Skin-Inspired Electronic Devices. Mater. Today 2014, 17 (7), 321–331.

(13) Rogers, J. A.; Someya, T.; Huang, Y. Materials and Mechanics for Stretchable Electronics. Science (80-. ). 2010, 327 (5973), 1603–1607.


35


Page 36 of 55

(14) Kim, D.-H.; Lu, N.; Ma, R.; Kim, Y.-S.; Kim, R.-H.; Wang, S.; Wu, J.; Won, S. M.; Tao, H.; Islam, A.; Yu, K. J.; Kim, T.; Chowdhury, R.; Ying, M.; Xu, L.; Li, M.; Chung, H.-J.; Keum, H.; McCormick, M.; Liu, P.; Zhang, Y.-W.; Omenetto, F. G.; Huang, Y.; Coleman, T.; Rogers, J. A. RESEARCH ARTICLES Epidermal Electronics.

Science (80-. ). 2011, 333 (September), 838–844.

(15) Sun, Y.; Choi, W. M.; Jiang, H.; Huang, Y. Y.; Rogers, J. A. Controlled Buckling of Semiconductor Nanoribbons for Stretchable Electronics. Nat. Nanotechnol. 2006,

1 (3), 201–207.

(16) Rivnay, J.; Owens, R. M.; Malliaras, G. G. The Rise of Organic Bioelectronics.

Chem. Mater. 2013, 26 (1), 679–685.

(17) Benight, S. J.; Wang, C.; Tok, J. B. H.; Bao, Z. Stretchable and Self-Healing Polymers and Devices for Electronic Skin. Prog. Polym. Sci. 2013, 38 (12), 1961– 1977.

(18) Sessolo, M.; Khodagholy, D.; Rivnay, J.; Maddalena, F.; Gleyzes, M.; Steidl, E.; Buisson, B.; Malliaras, G. G. Easy-to-Fabricate Conducting Polymer Microelectrode


36

Page 37 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Arrays. Adv. Mater. 2013, 25 (15), 2135–2139.

(19) Mattana, G.; Cosseddu, P.; Fraboni, B.; Malliaras, G. G.; Hinestroza, J. P.; Bonfiglio, A. Organic Electronics on Natural Cotton Fibres. Org. Electron. physics,

Mater. Appl. 2011, 12 (12), 2033–2039.

(20) Mostafalu, P.; Akbari, M.; Alberti, K. A.; Xu, Q.; Khademhosseini, A.; Sonkusale, S. R. A Toolkit of Thread-Based Microfluidics, Sensors, and Electronics for 3D Tissue Embedding for Medical Diagnostics. Microsystems Nanoeng. 2016, 2 (April).

(21) Akbari, M.; Tamayol, A.; Bagherifard, S.; Serex, L.; Mostafalu, P.; Faramarzi, N.; Mohammadi, M. H.; Khademhosseini, A. Textile Technologies and Tissue Engineering: A Path Toward Organ Weaving. Adv. Healthc. Mater. 2016, 5 (7), 751–766.

(22) Fallahi, A.; Khademhosseini, A.; Tamayol, A. Textile Processes for Engineering Tissues with Biomimetic Architectures and Properties. Trends Biotechnol. 2016, 34 (9), 683–685..


37


Page 38 of 55

(23) Nejad, H. R.; Punjiya, M. P.; Sonkusale, S. Washable Thread Based Strain Sensor for Smart Textile. In TRANSDUCERS 2017 - 19th International Conference on

Solid-State Sensors, Actuators and Microsystems; IEEE, 2017; pp 1183–1186.

(24) Sadeqi, A.; Rezaei Nejad, H.; Alaimo, F.; Yun, H.; Punjiya, M.; Sonkusale, S. R. Washable Smart Threads for Strain Sensing Fabrics. IEEE Sens. J. 2018, 18 (22), 9137–9144.

(25) Mostafalu, P.; Kiaee, G.; Giatsidis, G.; Khalilpour, A.; Nabavinia, M.; Dokmeci, M. R.; Sonkusale, S.; Orgill, D. P.; Tamayol, A.; Khademhosseini, A. A Textile Dressing for Temporal and Dosage Controlled Drug Delivery. Adv. Funct. Mater. 2017, 27 (41), 1–10.

(26) Lyu, B.; Punjiya, M.; Matharu, Z.; Sonkusale, S. An Improved PH Mapping Bandage with Thread-Based Sensors for Chronic Wound Monitoring. In Proceedings - IEEE

International Symposium on Circuits and Systems; IEEE, 2018; Vol. 2018-May, pp 1–4.

(27) Punjiya, M.; Nejad, H. R.; Mostafalu, P.; Sonkusale, S. PH Sensing Threads with


38

Page 39 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


CMOS Readout for Smart Bandages. In 2017 IEEE International Symposium on

Circuits and Systems (ISCAS); IEEE, 2017; pp 1–4.

(28) Punjiya, M.; Rezaei, H.; Zeeshan, M. A.; Sonkusale, S. A Flexible PH Sensing Smart Bandage with Wireless CMOS Readout for Chronic Wound Monitoring. In

TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems; IEEE, 2017; pp 1700–1702.

(29) Owyeung, R. E.; Panzer, M. J.; Sonkusale, S. R. Colorimetric Gas Sensing Washable Threads for Smart Textiles. Sci. Rep. 2019, 9 (1), 5607.

(30) Lee, J. B.; Subramanian, V. Organic Transistors on Fiber: A First Step towards

Electronic Textiles; 2003.

(31) Hamedi, M.; Forchheimer, R.; Inganäs, O. Towards Woven Logic from Organic Electronic Fibres. Nat. Mater. 2007, 6 (5), 357–362.

(32) Hamedi, M.; Herlogsson, L.; Crispin, X.; Morcilla, R.; Berggren, M.; Inganös, O. Fiber-Embedded Electrolyte-Gated Field-Effect Transistors for e-Textiles. Adv.


39


Page 40 of 55

Mater. 2009, 21 (5), 573–577.

(33) Tarabella, G.; Villani, M.; Calestani, D.; Mosca, R.; Iannotta, S.; Zappettini, A.; Coppedè, N. A Single Cotton Fiber Organic Electrochemical Transistor for Liquid Electrolyte Saline Sensing. J. Mater. Chem. 2012, 22 (45), 23830–23834.

(34) Müller, C.; Hamedi, M.; Karlsson, R.; Jansson, R.; Marcilla, R.; Hedhammar, M. Woven Electrochemical Transistors on Silk Fibers. Adv. Mater. 2011, 23 (7), 898– 901.

(35) Bonfiglio, A.; De Rossi, D.; Kirstein, T.; Locher, I. R.; Mameli, F.; Paradiso, R.; Vozzi, G. Organic Field Effect Transistors for Textile Applications. IEEE Trans. Inf.

Technol. Biomed. 2005, 9 (3), 319–324.

(36) Maccioni, M.; Orgiu, E.; Cosseddu, P.; Locci, S.; Bonfiglio, A. Towards the Textile Transistor: Assembly and Characterization of an Organic Field Effect Transistor with a Cylindrical Geometry. Appl. Phys. Lett. 2006, 89 (14), 143515.

(37) Kim, H. M.; Kang, H. W.; Hwang, D. K.; Lim, H. S.; Ju, B. K.; Lim, J. A. Metal-


40

Page 41 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Insulator-Semiconductor Coaxial Microfibers Based on Self-Organization of Organic Semiconductor:Polymer Blend for Weavable, Fibriform Organic FieldEffect Transistors. Adv. Funct. Mater. 2016, 26 (16), 2706–2714.

(38) Heo, J. S.; Kim, T.; Ban, S. G.; Kim, D.; Lee, J. H.; Jur, J. S.; Kim, M. G.; Kim, Y. H.; Hong, Y.; Park, S. K. Thread-Like CMOS Logic Circuits Enabled by ReelProcessed Single-Walled Carbon Nanotube Transistors via Selective Doping. Adv.

Mater. 2017, 29 (31), 1–8.

(39) Guinovart, T.; Bandodkar, A. J.; Windmiller, J. R.; Andrade, F. J.; Wang, J. A Potentiometric Tattoo Sensor for Monitoring Ammonium in Sweat. Analyst 2013,

138 (22), 7031–7038.

(40) Brannelly, N. T.; Hamilton-Shield, J. P.; Killard, A. J. The Measurement of Ammonia in Human Breath and Its Potential in Clinical Diagnostics. Crit. Rev. Anal. Chem. 2016, 46 (6), 490–501.

(41) Shimamoto, C.; Hirata, I.; Katsu, K. Breath and Blood Ammonia in Liver Cirrhosis.

Hepatogastroenterology. 2000, 47 (32), 443–445.


41


Page 42 of 55

(42) Bandodkar, A. J.; Molinnus, D.; Mirza, O.; Guinovart, T.; Windmiller, J. R.; ValdésRamírez, G.; Andrade, F. J.; Schöning, M. J.; Wang, J. Epidermal Tattoo Potentiometric Sodium Sensors with Wireless Signal Transduction for Continuous Non-Invasive Sweat Monitoring. 2013.

(43) Institute of Medicine. Sodium Intake and Intermediate Markers for Health Outcomes. In: Sodium Intake in Populations: Assessment of Evidence; Strom, B. L.; Yaktine, A. L.; Oria, M. Eds.; The National Academies Press: Washington, DC, 2013; pp 39-52.

(44) Sen, C. K. Wound Healing Essentials: Let There Be Oxygen. Wound Repair and

Regeneration. 2009, pp 1–18.

(45) Ameri, S. K.; Singh, P. K.; Angelo, A. J. D.; Panzer, M. J.; Sonkusale, S. R. Flexible 3D Graphene Transistors with Ionogel Dielectric for Low-Voltage Operation and High Current Carrying Capacity. 2016, 1–7.

(46) Lee, J.; Panzer, M. J.; He, Y.; Lodge, T. P.; Frisbie, C. D. Ion Gel Gated Polymer Thin-Film Transistors. J. Am. Chem. Soc. 2007, 129 (15), 4532–4533.


42

Page 43 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(47) Panzer, M. J.; Frisbie, D. Polymer Electrolyte-Gated Organic Field-Effect Transistors: Low-Voltage, High-Current Switches for Organic Electronics and Testbeds for Probing Electrical Transport at High Charge Carrier Density. J. Am.

Chem. Soc. 2007, 129 (20), 6599–6607.

(48) Panzer, M. J.; Frisbie, C. D. Exploiting Ionic Coupling in Electronic Devices: Electrolyte-Gated Organic Field-Effect Transistors. Adv. Mater. 2008, 20 (16), 3176–3180.

(49) Leighton, C. Electrolyte-Based Ionic Control of Functional Oxides. Nat. Mater. 2019, 18 (January), 13–18.

(50) Wang, S.; Ha, M.; Manno, M.; Daniel Frisbie, C.; Leighton, C. Hopping Transport and the Hall Effect near the Insulator–Metal Transition in Electrochemically Gated Poly(3-Hexylthiophene) Transistors. Nat. Commun. 2012, 3 (1), 1210.

(51) Lee, J.; Kaake, L. G.; Cho, H. J.; Zhu, X. Y.; Lodge, T. P.; Frisbie, C. D. Ion GelGated Polymer Thin-Film Transistors: Operating Mechanism and Characterization of Gate Dielectric Capacitance, Switching Speed, and Stability. J. Phys. Chem. C


43


Page 44 of 55

2009, 113 (20), 8972–8981.

(52) Ueno, K.; Hata, K.; Katakabe, T.; Kondoh, M.; Watanabe, M. Nanocomposite Ion Gels Based on Silica Nanoparticles and an Ionic Liquid: Ionic Transport, Viscoelastic Properties, and Microstructure. J. Phys. Chem. B 2008, 112 (30), 9013–9019.

(53) Ueno, K.; Imaizumi, S.; Hata, K.; Watanabe, M. Colloidal Interaction in Ionic Liquids: Effects of Ionic Structures and Surface Chemistry on Rheology of Silica Colloidal Dispersions. Langmuir 2009, 25 (2), 825–831.

(54) Ueno, K.; Watanabe, M. Silica Colloidal Suspensions in Ionic Liquids: Colloidal Stability and Fabrication of Ion Gels on the Basis of Colloidal Self-Assembly. In

ACS Symposium Series; 2009; Vol. 1030, pp 199–210.

(55) Ueno, K.; Inaba, A.; Ueki, T.; Kondoh, M.; Watanabe, M. Thermosensitive, Soft Glassy and Structural Colored Colloidal Array in Ionic Liquid: Colloidal Glass to Gel Transition. Langmuir 2010, 26 (23), 18031–18038.


44

Page 45 of 55 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(56) Fukaya, Y.; Iizuka, Y.; Sekikawa, K.; Ohno, H. Bio Ionic Liquids: Room Temperature Ionic Liquids Composed Wholly of Biomaterials. Green Chem. 2007, 9 (11), 1155– 1157.

(57) Zhao, D.; Liao, Y.; Zhang, Z. D. Toxicity of Ionic Liquids. Clean - Soil, Air, Water 2007, 35 (1), 42–48.

(58) Zhang, Q.; De Oliveira Vigier, K.; Royer, S. S.; Franc¸ois, F.; Je´roˆme, J. J. Deep Eutectic Solvents: Syntheses, Properties and Applications. This J. is Cite this

Chem. Soc. Rev 2012, 41, 7108–7146.

(59) Horowitz, A. I.; Panzer, M. J. High-Performance, Mechanically Compliant SilicaBased Ionogels for Electrical Energy Storage Applications. J. Mater. Chem. 2012,

22 (32), 16534.

(60) Popere, B. C.; Sanoja, G. E.; Thomas, E. M.; Schauser, N. S.; Jones, S. D.; Bartels, J. M.; Helgeson, M. E.; Chabinyc, M. L.; Segalman, R. A. Photocrosslinking Polymeric Ionic Liquids via Anthracene Cycloaddition for Organic Electronics. J.

Mater. Chem. C 2018, 6 (32), 8762–8769.


45


Page 46 of 55

(61) White, S. P.; Dorfman, K. D.; Frisbie, C. D. Operating and Sensing Mechanism of Electrolyte-Gated Transistors with Floating Gates: Building a Platform for Amplified Biodetection. J. Phys. Chem. C 2016, 120 (1), 108–117.

(62) Cho, J. H.; Lee, J.; Xia, Y.; Kim, B.; He, Y.; Renn, M. J.; Lodge, T. P.; Daniel Frisbie, C. Printable Ion-Gel Gate Dielectrics for Low-Voltage Polymer Thin-Film Transistors on Plastic. Nat. Mater. 2008, 7 (11), 900–906.

(63) Rabaey, J. M.; Chandrakasan, A.; Nikolic, B. Digital Integrated Circuits: A Design

Perspective, 2nd ed.; Pearson, Ed.; 2003.

(64) Fallis, A. . Principles of CMOS VLSI Design, a Systems Perspective, 2nd ed.; Addison-Wesley, 2013; Vol. 53.

(65) Mousavi, M. P. S.; Ainla, A.; Tan, E. K. W.; K. Abd El-Rahman, M.; Yoshida, Y.; Yuan, L.; Sigurslid, H. H.; Arkan, N.; Yip, M. C.; Abrahamsson, C. K.; et al. Ion Sensing with Thread-Based Potentiometric Electrodes. Lab Chip 2018, 18 (15), 2279–2290.


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Figure 1. (a) Schematic of a thread-based integrated transistor system for advanced sensing of biologically relevant ions. The sample from wound tissue is brought to the sensor area via a sampling thread that wicks the liquid up through the tissue while simultaneously suturing the wound site. Threads are used as a substrate for both the sensors and transistors for flexibility and softness resembling underlying skin and bring the electronic signal to the microcontroller (μC). The insets show a close-up of the multiplexed sensing architecture used. (b) The thread-based integrated transistor system sutured into chicken skin. The threads sutured into the chicken skin as a microfluidic sampler are highlighted for better visualization. This demonstrates the seamless biointegration of threads as a bioelectronics substrate. 338x107mm (96 x 96 DPI)


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Figure 2. (a) Optical image of the formed colloidal gel in an inverted glass vial. (b) Schematic illustration of the ionogel formed by colloidal interactions between silica nanoparticles (shown in blue) within the ionic liquid, EMI TFSI (shown in green). EMI TFSI’s chemical structure can be seen in the inset. (c) Capacitance versus frequency data shows the high capacitance levels achievable by using ionogel gating due to the formation of electrostatic double layers. 287x82mm (96 x 96 DPI)



Figure 3. Fabrication scheme of the thread-based transistors (TBTs). The initial linen thread (a) is knotted with source/drain Au wire contacts (b). Then, the active channel semiconductor (P3HT or CNTs) is drop cast onto the thread (c). The ionogel is swabbed on top of the area to form the gate layer (d). Finally, another Au wire serves as the gate electrode (e). (f) A schematic illustration of the ionogel-gated thread transistor viewed looking down the axis of the thread (not to scale) highlights the TBT geometry with the ionogel gate dielectric enabling all-around electrostatic gating, thus increasing active channel dimensions without the need to form a smaller gap between source and drain electrodes. 508x105mm (96 x 96 DPI)


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Figure 4. (a) Transfer and (b) output characteristics of a CNT TBT device. (c) Transfer and (d) output characteristics of a P3HT TBT device. 338x190mm (96 x 96 DPI)



Figure 5. (a) Transfer curve of a CNT TBT at different bending radii. (b) Threshold voltage values extracted from the transfer curves measured at different bending radii.


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Figure 6. Logic table, electrical schematic, and electrical measurements of different logic gates a) NAND b) NOR and c) NOT. Curves represent the two logic gate inputs, A and B, and the output from the circuit, Y. 214x184mm (96 x 96 DPI)



Figure 7. A setup of the multiplexer architecture is shown (a) with three working electrodes (WEs), each with a TBT in series. (b) Validation of the transistor as a switch using a sodium ion sensor in series with a CNT TBT. Unmodified OCP with TBT in series and ON. Negative potential could be due to slight leakage of TBT. (c) Validation of the transistor as a switch using an ammonium sensor in series with CNT TBT. The grey represents the raw data, with the smoothed curve in blue to correct for transient fluctuations occurring during the measurement. A schematic for the MUX device setup is shown in (d). (e) Demonstration of the MUX turn on of each different channel to read out corresponding WE signals. (f) Direct output of each WE read by the potentiostat shows a slight offset between the MUX readout and the direct output of the WEs, but this offset is consistent between the devices.


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82x44mm (96 x 96 DPI)


Highly Flexible Transistor Threads for All-Thread Based Integrated

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