Resilient graphene ultrathin flat lens in aerospace, chemical, and

Subscriber access provided by BOSTON COLLEGE

Functional Nanostructured Materials (including low-D carbon)

Resilient graphene ultrathin flat lens in aerospace, chemical, and biological harsh environment Guiyuan Cao, Han Lin, Scott Fraser, Xiaorui Zheng, Blanca del Rosal, Zhixing Gan, Shibiao Wei, Xiaosong Gan, and Baohua Jia ACS Appl. Mater. Interfaces, Just Accepted Manuscript • Publication Date (Web): 07 May 2019 Downloaded from http://pubs.acs.org on May 7, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 18 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

ACS Applied Materials & Interfaces

Resilient graphene ultrathin flat lens in aerospace, chemical, and biological harsh environments Guiyuan Cao, Han Lin*, Scott Fraser, Xiaorui Zheng, Blanca Del Rosal, Zhixing Gan, Shibiao Wei, Xiaosong Gan, Baohua Jia* Centre for Translational Atomaterials, Faculty of Engineering, Science and Technology, Swinburne University of Technology. John Street, Hawthorn, VIC 3122, Australia

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 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

ABSTRACT: The development of ultrathin flat lenses has revolutionized the lens technologies and holds a great promise to miniaturize the conventional lens system in integrated photonic applications. In certain applications, the lenses are required to operate in harsh and/or extreme environments, for example aerospace, chemical and biological environments. Under such circumstances, it is critical that the ultrathin flat lenses can be resilient and preserve their outstanding performance. However, majority of the demonstrated ultrathin flat lenses are based on metal or semiconductor materials that have poor chemical, thermal and UV stability, which limit their applications. Herein, we experimentally demonstrate a graphene ultrathin flat lens that can be applied in harsh environments for different applications, including low Earth orbit space environment, strong corrosive chemical environment (PH=0 and PH=14), and biochemical environment. The graphene lenses have extraordinary environmental stability and can maintain high level of structural integrity and the outstanding focusing performance under different test conditions. Thus it opens tremendous practical application opportunities for ultrathin flat lenses.

KEYWORDS: Reduce graphene oxide; Ultra-thin flat lens; Low Earth orbit space; Physiological environment; Acid-base tolerance


Page 2 of 18

Page 3 of 18 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


Introduction

The development of ultrathin flat lenses1-5 has revolutionized the lens technology towards miniaturization. Due to the advantages of flat and thin structure, ultra-light weight and the capability of achieving aberration-free high performance imaging in a broad spectral range6-11 ultrathin lenses have a great potential to replace conventional bulky lenses in many applications, including aerospace, where weight incurrs high cost; microfluidic devices for monitoring chemical reactions, where miniaturization holds the key; and biological processes, where high resolution in-situ observation is vital. In these applications, the lenses are required to be exposed to harsh and/or extreme environments, such as extremely high/low temperatures, bio-chemicals, corrosive chemicals, strong ultraviolet (UV) radiation, plasma radiation, atomic oxygen, or high vacuum. It is crucial that the ultrathin flat lenses can maintain their structure integrity and preserve the outstanding performance under those harsh conditions with low maintenance. The structural and performance stability of an ultrathin flat lens mainly depends on the constructing materials. Currently, most ultrathin flat lenses, including meta lens1, superoscillatory lens12 and plasmonic lens13-14 are made of metal/semiconductor materials that have instabilty in the above-mentioned harsh environments, limiting their applications in harsh environments (Supplementary Table S1).

Based on the extraordinary stability of graphene, here we designed and fabricated ultrathin flat lenses using pure reduced graphene oxide (rGO) (a material derived from graphene oxide, and with properties very close to graphene). The extraordinary thermal and chemical stabilities of rGO15-22 allow the ultrathin lens to work in various harsh environments, such as strong acid/alkaline solutions, extremely high/low temperature, strong UV radiation, plasma radiation, atomic oxygen (AO) and high vacuum. We experimentally simulate the harsh environments in the lab according to the parameters in the applications, namely low Earth orbit



Page 4 of 18

(LEO) environment, strong corrosive condition and biochemical conditions. For each type of environment, we test the rGO lens in the conditions for a certain amount of time. Then we study both the surface morphology, which indicates the structural integrity, and the focusing performance after each test. We use focal intensity distributions as a benchmark to identify the tiny change of the rGO lenses and verify the harsh environment stability with high accuracy. Our results show that the rGO lenses can maintain extraordinary focusing performance under almost all harsh environments. Thus, we demonstrate a resilient ultrathin flat lens that can be readily applied in multiple harsh environments for the first time. rGO lens design, fabrication, and characterization on cover glass According to the Rayleigh-Sommerfeld (RS) theory and the available refractive index of fully reduced GO23, a 30 μm focal length rGO flat lens with 150 nm thickness is designed. For the detailed lens design, we have developed an accurate method24 based on the RS diffraction theory that is able to unambiguously determine the radii of each ring without the optimization process. The RS design method is able to accurately design GO lenses with arbitrary NA and focal length. Here we consider a lens design composing of concentric rGO ring structures (Figure 1(a) & (b)). The thickness of the rGO film is chosen to provide at least π phase shift on the incident light. In this study, we used a He-Ne laser at the wavelength of 632.8 nm. 𝜆

Considering the refractive index of the rGO is around 2.1, the thickness should be 𝑡 = 2𝑛 ≈ 150 𝑛𝑚. The width of the ring is decided to provide significant diffraction effect, which is approximately a wavelength. Thus the width is 600 nm. The surface profile of the rGO rings is Gaussian shape due to laser fabrication process, which is confirmed by the optical profiler measurement shown in Figure 1(b). The overall diameter of the lens is 40 µm with a focal length of 30 µm. The ten radii of the rGO rings are listed in supplementary Table S2.


Page 5 of 18 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


The GO film is fabricated by filtration method, then transferred onto a cover glass (G409-2 cover glass, from PST Company). The rGO film is prepared by exposing the GO film under UV light (Olympus U-UlS100HG, USH-102D, 100 W, 200-600nm wavelength) for 3 hours. The rGO lens is fabricated using direct laser writing with a femtosecond laser25 (Coherent®, Libra, λ = 800 nm, pulse width = 100 fs, repetition rate = 10 kHz, the setup information can be found in Supplementary Figure S1) to ablate the rGO film. The transmission optical microscopic (50×) image of the fabricated rGO lens is shown in Figure 1(a). Figure 1(b) shows the topographic profile of the rGO lens measured by an optical profiler. One can see the approximate Gaussian profile of each rGO ring in the bottom cross-sectional profile in Figure 1(b), which is attributed to the Gaussian shaped focal spot of the fabrication laser beam. Figure 1(c) is the Raman shift of the rGO lens, in which we can see the signature D and G band peaks from the rGO material.

Figure 1. rGO ultrathin flat lens. (a) Transmission optical microscopic image of an rGO lens. (b) Topographic profile of the rGO ultrathin flat lens measured by an optical profiler and the cross sectional profile marked by the white dash line in (b). Harsh environment tests In the following, we discuss the performance of the rGO lenses according to different applications, namely LEO, strong acid and alkaline, and biochemical conditions. The conceptual drawings of these applications are shown in Figure 2.



Figure 2. Applications of rGO flat lenses (a) Imaging optical element for a satellite in aerospace. (b) Observing strong acid/alkaline chemical reactions. (c) Biophotonic microfluidic devices.

Low Earth orbit (LEO) condition The application of the rGO lens in aerospace is schematically shown in Figure 2(a), in which the ultrathin ultra-light weight rGO lenses are expected to function as the imaging lens to replace the current bulky lens system. In this way, the overall weight of the satellite can be significantly reduced, which saves largely the launching cost of the satellite that is proportional to weight. rGO lenses are also able to achieve high resolution images due to a much higher numerical aperture and has the potential to compensate for the aberration. Thus, it is important to simulate the space environment and test the performance stability of the rGO lenses. The harsh environment in the LEO condition includes exposure to extreme heat and cold cycles, strong UV radiation, ultrahigh vacuum, AO, and high energy radiation26-28. Testing and qualification of rGO lenses exposed to these extreme conditions can provide data to enable the manufacturing of long-life reliable rGO lenses used on Earth as well as in the sophisticated satellite and spacecraft components. According to the NASA standard29, we first simulate the strong UV radiation environment, which is 24 hours exposing to UV light (Olympus U-UlS100HG, USH-102D, 100 W, 200-


Page 6 of 18

Page 7 of 18 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


600nm wavelength). On the other hand, in order to simulate the ultrahigh vacuum environment, the rGO lenses were placed in a vacuum chamber for 24 hours with 0.01 Pa pressure at 100°C (Supplementary Figure S3). Following the ultrahigh vacuum test, the same rGO lenses were heated to 200°C in a vacuum oven for 24 hours and then immersed in liquid nitrogen (~-196°C) for 1 hour (Supplementary Figure S4) to simulate the thermal cycles from +120°C to -120°C taking place in the LEO environment. There is no visible change of the rGO lens from the optical microscopic image after each test (Figure 3(a)). In the meantime, the focusing performance is measured using a microscopic imaging setup with 633 nm wavelength after each test (Supplementary Figure S2). The final and the original focusing intensity distributions are shown in Figure 3(b) as well as the cross-sectional profiles along x (Figure 3(c), marked by the black dash line) and z directions (Figure 3(d), marked by the black dash line). From the figure, one can see that the diffraction-limited three-dimensional (3D) high focusing performance of the rGO flat lens is well preserved. The detailed parameters (focal length, full width at half maximum (FWHM) on x and z directions) are listed in Table 1. The changes in all the focusing parameters in Table 1 are within 2.4%. Considering the resolution of the imaging setup in the measurement, it was confirmed that the focusing performance of the rGO lens has not been affected.



Figure 3. (a) Transmission optical microscopic images of rGO lenses after each experiment, including 24 hours UV exposure, 1 hour in liquid nitrogen, 24 hours in 200 °C,24 hours at 100 °C in vacuum condition. (b) Focal intensity distributions in the lateral and axial planes of the original and after all the four harsh environments attacking the rGO lenses. (c) Intensity distributions along the black dash lines parallel to x axis in the axial planes. (d) Intensity distributions along the black dash lines parallel to z axis in the lateral planes.


Page 8 of 18

Page 9 of 18 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


Table 1. Focal lengths and FWHMs on x and z axes of the rGO lenses after each experiment

Original result FWHM on x (μm)

0.56±0.07

Focal length (μm)

30.0±0.1

FWHM on z (μm)

4.1±0.1

200 ℃ heating

Liquid nitrogen

Vacuum

0.55±0.07 (-1.8%) 30.1±0.1 (0.3%) 4.2±0.1 (2.4%)

0.56±0.07 (0%) 30.1±0.1 (0.3%) 4.2±0.1 (2.4%)

0.57±0.07 (1.8%) 30.0±0.1 (0%) 4.2±0.1 (2.4%)

AO is the most hazardous constituent in LEO for most carbon based material27. The density of AO is approximately 2~8×109 atom/cm3 at about 300 km altitude30 and the kinetic energy of AO particle is approximate 5.2 eV due to the ~8 km/s velocity of the spacecraft, which leads to the flux range of AO31 approximately from 1014 to 1015 atoms/cm2s. We used a Samco RIE101iPH (Supplementary Figure S3) to generate oxygen plasma to simulate the AO radiation (the schematic of the process is shown in Figure 4(a)). The pressure in the plasma chamber was 0.37 Pa, the gas composition ratio of oxygen to argon (O2: Ar) was 2:8; the power of radiofrequency plasma source was 200 W to obtain the ~9.77×1013 atom/cm3; the bias power was 30 W to give AO particles 5.2 eV kinetic energy. According to the ratio of the density being simulated, 1 second in the experiment corresponds to 5.5 hours in the LEO condition. Our rGO lenses were tested under AO radiation for 5, 15, 30, 45 and 60 s, separately. We found the rGO lens was completely removed from the substrate and lost focusing function after 60 s, which means the lifetime of the rGO under AO condition is about 13 days in the LEO condition.



Figure 4. rGO lens treated by AO radiation. (a) Scheme of AO radiation. (b) Thickness change with the increase of AO radiation time. (c) rGO lens profiles evolution after different AO radiation time. The optical microscopic images of the rGO lenses treated by AO radiation for 5, 15, 30 and 45 s are shown in Figure 4(c). The thickness of the rGO lenses decreases as the AO treatment time increases as shown in Figure 4(b). The fit line is a second-order polynomial, which means the decrease rate of the thickness increases with prolonged AO treatment time. The etching of rGO lenses is uniform, which offers the potential of the rGO lenses to maintain the focal spots before all the rGO layers were removed. As a result, the focusing performance of the rGO lenses can be maintained (Figure 5(a)). The FWHMs and focal lengths of the rGO lenses after 5, 15, 30 and 45 s AO radiation are listed in Table 2. The differences between them and the original experimental results are insignificant. These are verified by theory simulation (Supplementary Table S3), which also shows negligible change (within 1.6%) for the FWHM and focal lengths when the rGO thickness reduces. The results indicate that to achieve a longer lifetime of the rGO lens, one simple potential solution is to increase the thickness of the rGO lens. However,


Page 10 of 18

Page 11 of 18 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


for long period aerospace applications, it is better to cover the rGO lenses to protect specially from the AO condition or simply to replace the worn out rGO lenses with new ones due to its low cost. In summary, the rGO lenses can remain intact under all LEO conditions except for the long-term AO radiation exposure. Therefore, protection or replacement is only necessary if the rGO lenses are exposed directly to AO radiation over an extended period of time.

Figure 5. Focal intensity distributions of the rGO lenses after AO radiation (a) Intensity distributions in the lateral and axial planes. (b) Intensity distributions along the black dash lines parallel to x axis in the axial planes. (c) Intensity distributions along the black dash lines parallel to z axis in the lateral planes.



Page 12 of 18

Table 2. Focal lengths and FWHMs on x and z axes after different AO radiation time.

FWHM on x (μm) Focal length (μm) FWHM on z (μm)

5s

15 s

30 s

45 s

0.54±0.07 (-3.6%) 30.0±0.1 (0%) 4.3±0.1 (4.9%)

0.52±0.07 (-7.1%) 30.1±0.1 (0.3%) 3.9±0.1 (-4.9%)

0.54±0.07 (-3.6%) 30.2±0.1 (0.7%) 4.6±0.1 (12%)

0.51±0.07 (-8.9%) 30.0±0.1 (0%) 4.6±0.1 (12%)

Harsh chemical environment

Due to the ultrathin nature, the rGO lenses can be integrated with chemical containers to insitu observe the localized chemical reaction or acquire the spectral information of limited amount of chemicals. The chemical reaction may involve strong acid/alkaline solution as shown in Figure 2(b), and the observing process may last for extended period of time, for example a few days. Therefore, it is important to understand the performance stability of the rGO lenses under such circumstances for a relatively long period of time. In this study, the rGO lenses were immersed in a strong acid solution (H2SO4, PH=0) for 7 days at room temperature, followed by immersion in strong alkaline solution (KOH, PH=14) for 7 days (Supplementary Figure S5). The schematic of the process is shown in Figure 6(a). The optical microscopic images of the rGO lenses after each test are shown in Figures 6(b) and (c). No visible damage can be observed. The focal intensity distributions were measured after each experiment, as shown in Figure 6(d). For further detailed comparisons, the intensity distributions along x and z directions (marked by the black dash lines) of all results were plotted in Figures 6(e) & (f) and compared with the original lens. The FWHM on the x direction of the rGO lens after immersing in acid and alkaline solutions are 0.59 μm and 0.60 μm; FWHM on z direction are 4.0 and 4.1 μm; the focal lengths are both 30.0 μm as listed in Table 3. Considering the imaging resolution of the characterization setup, it is confirmed that the high focusing performance has


Page 13 of 18 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


not been altered. Therefore, the rGO lens has remarkable resilience to strong acid/alkali solutions and can be used in harsh chemical environments.

Figure 6. rGO lens treated by strong acid/alkaline. (a) Scheme of strong acid/alkaline tests. (b) Microscopic images of the rGO lens after immersing in strong acid (PH=0) solution. (c) Microscopic images of the rGO lens after immersing in strong alkaline (PH=14) solution. (d) Intensity distributions in the lateral and axial planes after strong acid/alkaline tests. (e)



Page 14 of 18

Intensity distributions along the black dash lines parallel to x axis in the axial planes. (f) Intensity distributions along the black dash lines parallel to z axis in the lateral planes. Table 3. Focal lengths and FWHM on x and z axes of the rGO lenses after strong acid/alkaline and phosphate-buffered saline solution test.

Original result FWHM on x (μm) Focal length (μm) FWHM on z (μm)

0.56±0.07 30.0±0.1 4.1±0.1

Acid

Alkaline

PBS

0.59±0.07 (5.3%) 30.0±0.1 (0%) 4.0±0.1 (-2.5%)

0.60±0.07 (7.1%) 30.0±0.1 (0%) 4.1±0.1 (0%)

0.54±0.07 (-3.6%) 30.1±0.1 (0.3%) 4.3±0.1 (4.9%)

Biochemical environment

On the other hand, the ultrathin rGO flat lenses can be integrated into microfluidic devices in biophotonic applications as illustrated in Figure 2(c). One commonly used solution in biological research is the phosphate-buffered saline (PBS)32-34 (Supplementary Figure S5), which is a water-based salt solution containing disodium hydrogen phosphate, sodium chloride and, in some formulations, potassium chloride, and potassium dihydrogen phosphate. The buffer helps to maintain a constant PH (PH=7.5±0.1). To verify the stability of the rGO lens in a biological body, the PBS solution has been used to immerse the rGO lens for 24 hours at 37°C. The optical microscopic image of the rGO lens after the test is shown in Figure 7(a). In addition, the optical profiler image was taken to confirm that the surface of the rGO lens is not affected by the PBS solution. The focal spot has been measured as shown in Figure 7(c). The intensity distributions in the axial and lateral planes show no obvious difference compared with the original experimental results, which means that the rGO lens can be directly used in the microfluidic devices in contact with the PBS solution. Therefore the rGO lens can be


Page 15 of 18 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


potentially applied in living body conditions, such as in the case of micro-fiber endoscopy. In addition, after the above experiments, we find the adhesion of rGO film to the substrate is quite strong, which is contributed to Van der Waal’s force and the strong hydrophobic force between the rGO and the cover glass35.

Figure 7. rGO lens after the PBS test. (a) Microscopic images of the rGO lens after immersing in PBS for 24 hours. (b) Topological profile of the rGO lens after PBS test. (c) Intensity distributions in the lateral and axial planes after PBS test. (d) Intensity distributions along the black dash lines parallel to x axis in the axial planes. (e) Intensity distributions along the black dash lines parallel to z axis in the lateral planes.



Conclusion The performance stability of the rGO ultrathin flat lenses was tested in a number of harsh environments according to the requirements of diverse applications. The harsh environment includes LEO condition, strong corrosive chemical and biochemical conditions. There is no measurable deterioration in either the surface morphology or the highly sensitive focusing performance in most of the circumstances except for the long-term AO radiation direct exposure. Nevertheless, with proper protection against AO radiation, the rGO lens can be safely applied in the aerospace environment. The encouraging results suggest rGO is a promising ultra-stable material potentially useful for a variety of practical circumstances, in particular where harsh environments and low maintenance are required for example strong corrosive chemical condition or biochemical condition without any protection. On the fabrication side, recently we have developed a large-scale GO film formation method22, which has the capability to produce GO films of arbitrarily large sizes with nanometer thickness control. In addition, the commercial laser fabrication system is also scalable for meter-sized samples to be processed. AUTHOR INFORMATION Corresponding Author *E-mail: [email protected]; [email protected]. Acknowledgements B.J. and H.L. acknowledge the support from the Defense Science and Technology and B. J. acknowledges support from the Australia Research Council through the Industrial Transformation Training Centres scheme (IC180100005). Notes The authors declare no competing financial interest. Reference


Page 16 of 18

Page 17 of 18 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


1. Khorasaninejad, M.; Chen, W. T.; Devlin, R. C.; Oh, J.; Zhu, A. Y.; Capasso, F., Metalenses at Visible Wavelengths: Diffraction-limited Focusing and Subwavelength Resolution Imaging. Science 2016, 352 (6290), 1190-1194. 2. Aieta, F.; Genevet, P.; Kats, M. A.; Yu, N.; Blanchard, R.; Gaburro, Z.; Capasso, F., Aberrationfree Ultrathin Flat Lenses and Axicons at Telecom Wavelengths Based on Plasmonic Metasurfaces. Nano Lett 2012, 12 (9), 4932-4936. 3. Yu, N.; Genevet, P.; Kats, M. A.; Aieta, F.; Tetienne, J.-P.; Capasso, F.; Gaburro, Z., Light Propagation with Phase Discontinuities: Generalized Laws of Reflection and Refraction. Science 2011, 1210713. 4. Qin, F.; Huang, K.; Wu, J.; Teng, J.; Qiu, C. W.; Hong, M., A Supercritical Lens Optical Label‐Free Microscopy: Sub‐Diffraction Resolution and Ultra‐Long Working Distance. Adv Mater 2017, 29 (8), 1602721. 5. Zheng, X.; Jia, B.; Lin, H.; Qiu, L.; Li, D.; Gu, M., Highly Efficient and Ultra-broadband Graphene Oxide Ultrathin Lenses with Three-dimensional Subwavelength Focusing. Nat Commun 2015, 6, 8433. 6. Gao, H. W.; Hyun, J. K.; Lee, M. H.; Yang, J. C.; Lauhon, L. J.; Odom, T. W., Broadband Plasmonic Microlenses Based on Patches of Nanoholes. Nano Lett 2010, 10 (10), 4111-4116. 7. Chen, W. T.; Zhu, A. Y.; Sanjeev, V.; Khorasaninejad, M.; Shi, Z.; Lee, E.; Capasso, F., A Broadband Achromatic Metalens for Focusing and Imaging in the Visible. Nature Nanotechnology 2018, 13 (3), 220-226. 8. Khorasaninejad, M.; Aieta, F.; Kanhaiya, P.; Kats, M. A.; Genevet, P.; Rousso, D.; Capasso, F., Achromatic Metasurface Lens at Telecommunication Wavelengths. Nano Lett 2015, 15 (8), 53585362. 9. Li, Z.; Zhang, T.; Wang, Y.; Kong, W.; Zhang, J.; Huang, Y.; Wang, C.; Li, X.; Pu, M.; Luo, X., Achromatic Broadband Super‐resolution Imaging by Super‐oscillatory Metasurface. Laser & Photonics Reviews 2018, 12 (10), 1800064. 10. Wang, Y.; Yun, W.; Jacobsen, C., Achromatic Fresnel Optics for Wideband Extremeultraviolet and X-ray Imaging. Nature 2003, 424 (6944), 50-53. 11. Kong, X.-T.; Khan, A. A.; Kidambi, P. R.; Deng, S.; Yetisen, A. K.; Dlubak, B.; Hiralal, P.; Montelongo, Y.; Bowen, J.; Xavier, S., Graphene-based Ultrathin Flat Lenses. Acs Photonics 2015, 2 (2), 200-207. 12. Yuan, G. H.; Rogers, E. T. F.; Zheludev, N. I., Achromatic super-oscillatory lenses with subwavelength focusing. Light: Science & Applications 2017, 6 (9), e17036. 13. Spektor, G.; David, A.; Gjonaj, B.; Bartal, G.; Orenstein, M., Metafocusing by a Metaspiral Plasmonic Lens. Nano Lett 2015, 15 (9), 5739-5743. 14. Liu, Z.; Steele, J. M.; Srituravanich, W.; Pikus, Y.; Sun, C.; Zhang, X., Focusing Surface Plasmons with a Plasmonic Lens. Nano Lett 2005, 5 (9), 1726-1729. 15. Zhu, Y.; Murali, S.; Cai, W.; Li, X.; Suk, J. W.; Potts, J. R.; Ruoff, R. S., Graphene and Graphene Oxide: Synthesis, Properties, and Applications. Adv Mater 2010, 22 (35), 3906-3924. 16. Novoselov, K. S.; Fal, V.; Colombo, L.; Gellert, P.; Schwab, M.; Kim, K., A Roadmap for Graphene. Nature 2012, 490 (7419), 192. 17. Geim, A. K.; Novoselov, K. S., The Rise of Graphene. In Nanoscience and Technology: A Collection of Reviews from Nature Journals, World Scientific: 2010; pp 11-19. 18. Loh, K. P.; Bao, Q.; Ang, P. K.; Yang, J., The Chemistry of Graphene. Journal of Materials Chemistry 2010, 20 (12), 2277-2289. 19. Zhao, J.; Wang, Z.; White, J. C.; Xing, B., Graphene in the Aquatic Environment: Adsorption, Dispersion, Toxicity and Transformation. Environmental Science & Technology 2014, 48 (17), 999510009. 20. Lin, H.; Sturmberg, B. C.; Lin, K.-T.; Yang, Y.; Zheng, X.; Chong, T. K.; de Sterke, C. M.; Jia, B., 90 nm-thick Graphene Metamaterial for Strong, Extremely Broadband Absorption of Unpolarized Light. Nature Photonics 2019, 13 (4), 270–276. 21. Zheng, X.; Lin, H.; Yang, T.; Jia, B., Laser Trimming of Graphene Oxide for Functional Photonic Applications. J Phys D Appl Phys 2017, 50, 074003.



22. Yang, Y.; Lin, H.; Zhang, B. Y.; Zhang, Y.; Zheng, X.; Yu, A.; Hong, M.; Jia, B., Graphenebased Multilayered Metamaterials with Phototunable Architecture for on-chip Photonic Devices. ACS Photonics 2019, 6 (4), 1033-1040. 23. Li, X.; Zhang, Q.; Chen, X.; Gu, M., Giant Refractive-index Modulation by Two-photon Reduction of Fluorescent Graphene Oxides for Multimode Optical Recording. Sci Rep-Uk 2013, 3, 2819. 24. Cao G Y; Gan X S; Lin H; Jia B H, An Accurate Design of Graphene Oxide Ultrathin Flat Lens Based on Rayleigh-Sommerfeld Theory. Opto-Electronic Advances 2018 1(7), 180012. 25. Wang, S.; Ouyang, X.; Feng, Z.; Cao, Y.; Gu, M.; Li, X., Diffractive Photonic Applications Mediated by Laser Reduced Graphene Oxides. Opto-Electronic Advances 2018, 1 (2), 1700020117000208. 26. Loeblein, M.; Bolker, A.; Tsang, S. H.; Atar, N.; Uzan-Saguy, C.; Verker, R.; Gouzman, I.; Grossman, E.; Teo, E. H. T., 3D Graphene-Infused Polyimide with Enhanced Electrothermal Performance for Long-Term Flexible Space Applications. Small 2015, 11 (48), 6425-6434. 27. Han, J. H.; Kim, C. G., Low Earth Orbit Space Environment Simulation and its Effects on Graphite/Epoxy Composites. Compos Struct 2006, 72 (2), 218-226. 28. Grossman, E.; Gouzman, I., Space Environment Effects on Polymers in Low Earth Orbit. Nucl Instrum Meth B 2003, 208, 48-57. 29. Miria M. Finckenor, K. K. d. G., A Researcher's Guide to : Space Environmental Effects. NASA: 2005. 30. Teichman, L. A., NASA/SDIO Space Environmental Effects on Materials Workshop. National Aeronautics and Space Administration Hampton va Langley Research Center: 1989. 31. Cvelbar, U.; Pejovnik, S.; Mozetie, M.; Zalar, A., Increased Surface Roughness by Oxygen Plasma Treatment of Graphite/Polymer Composite. Applied Surface Science 2003, 210 (3-4), 255-261. 32. Goldstein, S.; Czapski, G.; Lind, J.; Merényi, G., Tyrosine Nitration by Simultaneous Generation of⋅ NO and O⨪ 2 under Physiological Conditions HOW THE RADICALS DO THE JOB. Journal of Biological Chemistry 2000, 275 (5), 3031-3036. 33. Lo, T.; Westwood, M. E.; McLellan, A. C.; Selwood, T.; Thornalley, P. J., Binding and Modification of Proteins by Methylglyoxal under Physiological Conditions. A Kinetic and Mechanistic Study with N Alpha-acetylarginine, N Alpha-acetylcysteine, and N Alpha-acetyllysine, and Bovine Serum Albumin. Journal of Biological Chemistry 1994, 269 (51), 32299-32305. 34. Beckman, J. S.; Ischiropoulos, H.; Zhu, L.; van der Woerd, M.; Smith, C.; Chen, J.; Harrison, J.; Martin, J. C.; Tsai, M., Kinetics of Superoxide Dismutase-and Iron-catalyzed Nitration of Phenolics by Peroxynitrite. Archives of Biochemistry and Biophysics 1992, 298 (2), 438-445. 35. Drelich, J.; Mittal, K. L., Atomic Force Microscopy in Adhesion Studies. CRC Press: 2005.


Page 18 of 18

Resilient graphene ultrathin flat lens in aerospace, chemical, and

Recommend Documents