Quartz Crystal Microbalance with approximately uniformly sensitivity

Subscriber access provided by UNIVERSITY OF THE SUNSHINE COAST

Letter

Quartz Crystal Microbalance with approximately uniformly sensitivity distribution Xianhe Huang, Qingsong Bai, Wei Pan, and Jianguo Hu Anal. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.analchem.8b01529 • Publication Date (Web): 06 May 2018 Downloaded from http://pubs.acs.org on May 6, 2018

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 8 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

Analytical Chemistry

Quartz Crystal Microbalance with approximately uniformly sensitivity distribution Xianhe Huang,∗,† Qingsong Bai,†,‡ Wei Pan,† and Jianguo Hu† † ‡

School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China Electrical & Computer Engineering Department, University of California, Los Angeles, CA, 90095, USA.

Abstract: The non-uniformity of QCMs’ mass sensitivity distribution is a disadvantage to practical applications. Through theoretical calculations, we found that common ring electrode QCMs could obtain approximately uniformly sensitivity distribution by carefully selecting the inner and outer diameters and mass loading factor of the electrode. A series of experiments were carried out using 10 MHz ring electrode QCMs with an inner diameter of 2 mm, an outer diameter of 5 mm and a loading factor R of 0.0044. The experimental results proved that its mass sensitivity distribution is approximate uniformly. This special designed ring electrode QCMs is suitable and convenient for highly accurate measurements.

Introduction The advent of quartz crystal microbalances (QCMs) has opened a research area at the intersection of piezoelectric device and ultra-small mass sensing.1-3 QCMs consist of a thin vibrating quartz wafer sandwiched between two metal excitation electrodes, and have attracted significant attention due to their unprecedented simple structure, high mass sensitivity, low cost and the ability to operate in both gas and liquid phase. A QCM, is essentially a balance that could be used to precisely measure ultra-small masses in real-time, allowing the user to closely follow extremely subtle changes. Over the last few decades, QCMs have been used in a growing number of technology and research applications, such as surface interaction processes monitors,4-7 piezoelectric immunosensors,8-11 nanoscale characterization tools11-15 and various specific molecule sensors.16-21 Sauerbrey equation has been used to describe the interfacial mass changes through the mass dependence of the QCM resonant frequency. But it is worthy to note that the mass sensitivity distribution of QCMs may differ greatly depending on the material, shape, thickness and size of the metal electrodes, rather than having the same mass sensitivity in whole surface. For the most common QCMs coated with “m-m” and “n-m” type of electrodes, the mass sensitivity of QCM is distributed as an approximate Gaussian curve in the radial direction because of the energy trap effect of quartz crystal resonator. The large non-uniformity of the mass sensitivity could bring about significant errors, which limits its performance in practical applications. To weaken this disadvantage, pioneers designed ring electrode QCMs with bimodal distribution curves of mass sensitivity.22 But ∗ Corresponding authors. E-mail addresses: [email protected]

1

ACS Paragon Plus Environment

Analytical Chemistry 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 large difference between the peak points and the trough of the mass sensitivity distribution of ring electrode QCM still resulted in obvious non-uniformity. For instance, Fabien Josse et. al analyzed the mass sensitivity distribution of 11-MHz ring electrode QCMs with various values of the electrode mass loading factor R, the maximum difference of mass sensitivity between two peak points are 24%, 83% and 97% for R = 0.002, 0.006 and 0.012, respectively.22 Moreover, we designed dot-ring and double ring electrode QCMs at our previous work to improve the uniformity of the mass sensitivity.23 While these two designs result in relatively low mass sensitivity non-uniformity, the complex configuration is an issue in sensor applications. In this letter we present that for ring electrode QCMs, beyond the electrode loading factor, the inner and outer diameters of ring electrode also exert significant influence on the distribution of its mass sensitivity. Therefore, for ring electrode QCMs, when the electrode loading factor and the inner and outer diameters were selected properly, its mass sensitivity distribution could be approximately uniform. Mass sensitivity distributions of 10 MHz AT-cut QCMs with different electrode loading factor and the inner and outer diameters are theoretically calculated, the results shown in Figure 1. Note that R=0.0044 and R=0.0088 correspond to electrode thickness of 500 Å and 1000 Å, respectively. As Figure 1 (a) shows, a 10 MHz ring electrode QCM (the ring electrode of which with an inner diameter of 2 mm, an outer diameter of 5 mm and a loading factor R of 0.0044) has approximate uniform mass sensitivity distribution.

Figure 1. Mass-sensitivity distribution profiles for AT-cut 10 MHz QCMs. Red line represents the electroded region, green line represents the partially electroded region and blue line represents the non-electroded region. (a) The

inner and outer diameters of ring electrode are 2 mm and 5 mm, the electrode loading factor R=0.0044. (b) The inner and outer diameters of ring electrode are 2 mm and 5 mm, the electrode loading factor R=0.0088. (c) The inner and outer diameters of ring electrode are 4 mm and 110 mm, the electrode loading factor R=0.0044.

2


Page 2 of 8

Page 3 of 8 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


Experimental It is difficult to directly measure the mass sensitivity of QCMs precisely, therefore, the mass sensitivity measurement results in reported researches are usually relative values or normalized results.24-27 In our previous work,28 we presented the equivalent mass sensitivity which considers both the Gaussian distribution characteristic of mass sensitivity and the influence of electrodes on the mass sensitivity. Meanwhile, a technique to verify the sensitivity distribution of QCMs was presented, which consist of plate rigid gold films (with various diameters) on the center of QCMs surface, and then the theoretical frequency shift could be calculated according to

∆ = −

∆

2 1

where ∆ and ∆ are mass change and frequency shift, respectively, is mass sensitivity, is the distance from the center, is the radius of the specified circular region where mass loading attached on. In this letter, to verify the approximate uniform mass sensitivity distribution shown in Figure 1(a), a series of experiments which plate rigid gold films with different diameters on QCMs were performed. Experimental environment was selected in a class 10000 ultra-clean room of Wintron Electrionic Co., Ltd (Zhengzhou City, Henan Province, China). The ambient temperature in the ultra-clean room is maintained at 23 ºC. Fifteen “ plano-plano” shape quartz wafers with a fundamental frequency of 10 MHz and a diameter of 8.7 mm were used in the experiment. To verify the mass sensitivity distribution, these QCMs were divided into 3 groups and plated with thin gold films with different diameters. The first plating process is to plate electrodes onto the bare quartz wafers to constitute QCMs. According to theoretical analysis, ideal ring electrodes should be as Figure 2 (a) shows. But in consideration of convenience of practical applications, the actual topside and backside electrode was shown as Figure 2(b). During the manufacturing process, a 0.3 mm width defect belt will be caused in the upper ring electrode of the QCMs, because of manufacture restrictions (a circular mask is needed to cover the internal part of the ring, and this circular mask must be connected to other part through a mechanical beam which results in a defect belt of the ring electrode). (a)

(b) 0.3 mm 0.5 mm

Gold electrodes

Electrode contact pads

d2

Defect belt

0.5 mm

t1 d1

Figure 2. The ideal ring electrode QCM and actual ring electrode QCM. (a) The angled view (upper) and sideview (lower) of the ideal ring electrode QCM, where t1 is the thickness of the electrode, d1 3



Page 4 of 8

and d2 are the outer and inner diameters of electrode respectively. (b) The ring-electrode on the topside (upper) and circle-electrode on the backside (lower) of actual ring electrode QCM. In the first plating process, all the 15 quartz wafers were plated with gold electrodes (ring-electrode and circle-electrode for each side respectively) as Figure 2(b) shows, note that the thicknesses of electrodes are 500 Å. Their resonant frequencies were measured and recorded as . In the second plating process, group A, B and C were plated with gold films with a diameter of 1.0 mm, 2.0 mm and 3.0 mm onto the circle-electrode side, respectively. The plated film’s thickness are 500 Å. Their resonant frequencies after second plating were measured and recorded as . Therefore, ∆ = − is the frequency shift caused by the thin gold film which was been plated in the second plating process. Note that these quartz wafers and electrodes are circular, so the angular direction has not been considered. Figure 3 is a schematic of the experimental set-up.

S&A5600 plating system

Every wafer plated twice use S&A5600

First plating

Second plating Group A (5 QCMs) de=1.0 mm, te=500 Å

Group B (5 QCMs) de=2.0 mm, te=500 Å 15 quartz wafers

15 QCMs d1=5 mm, d2=2 mm t1=500 Å

Group C (5 QCMs) de=3.0 mm, te=500 Å

f1

f2 Frequency measurement use S&A250B-1 network analyzer

Figure 3. Schematic diagram of the experimental set-up. The equipment used in plating process is the S&A5600 BASE PLATING SYSTEM (Saunders & Associates, LLC. Phoenix, Arizona 85050 USA). The coating thickness is set by the equipment program. 4


Page 5 of 8 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


Results and discussion QCMs are usually modeled electrically by the Butterworth-Van Dyke (BVD) equivalent circuit which is an approximation of the electrical characteristics of the QCM.29 For the QCMs after first plating, according to BVD equivalent circuit, the static capacitance is 4.5 pF, the motional capacitance of the QCM is 18.0 fF, the motional resistance is 18Ω, these parameters are reasonable which shows that the electrodes thickness (500 Å) and the electrode loading factor R=0.0044 for 10 MHz QCM are suitable. The frequencies of all the 15 QCMs (3 groups) were measured use the S&A250B-1 network analyzer (Saunders & Associates, LLC. Phoenix, Arizona 85050 USA) with zero-phase method (with a driving power of 0 dBm), and the results are shown in and are the average value and the standard deviation of ∆ , respectively. ∆ is Table 1. ∆ the mass change caused by the second plating. C∗QCM is the equivalent mass sensitivity in the area coated with gold film.28 ∆ and are the theoretical frequency change according to Eq. 1 and the , respectively. error between ∆ and ∆ The best standard deviation (122.3 Hz) in these experiments is obtained in the group C, and the maximum standard deviation (183.1 Hz) is obtained in group B. This low standard deviation shows the high stability of the experimental system and the environment.

Table 1 Experimental results and theoretic values. ∆ (Hz) ∆ (Hz) (Hz)

∆ (kg)

A

B

990 950 1070 1050 1310

4272 4002 4341 3996 4450

1074

4212.2

125.5

C

7.587 × 10

10839

10644

10759

122.3 -9

3.035 × 10

6.828 × 10-9

∗ CQCM (Hz/kg)

1.37 × 1012

1.39 × 1012

1.38 × 1012

∆ (Hz)

1039.4

4218.7

9422.6

-3.26 %

0.15 %

12.97%

11009

10827.2

183.1 -10

10885

As Table 1 shows, for group A, B and C, while the sizes of coated films are various, the equivalent mass sensitivity C∗QCM within coated area are very close, which verified that the mass sensitivity of the QCMs distributed approximately uniformly. Moreover, for group A and group B, the deviation between the theoretical frequency change and the experimental results are small. For group C, the error between the theoretical and experimental results reached 12.97%, this could be due to the existence of the electrode leads and the deficiency belt of the ring electrode as Figure 2(b) shows, which will exert influence on the mass sensitivity. The diameters of the coated gold films are 3 mm in group C, which exceeded the inner dimeter of the ring electrode and covered the deficiency belt of the ring electrode. Therefore, the error in group C could be caused by the sensitivity deviation between the actual ring electrode QCM and the ideal ring electrode QCM.

5



Conclusion The theoretical calculation result shows that through carefully choosing the inner and outer diameters and mass loading factor of the electrode, common ring electrode QCMs could obtain approximately uniformly sensitivity distribution. To verify the sensitivity distribution uniformity of 10 MHz ring electrode QCMs with an inner diameter of 2 mm, an outer diameter of 5 mm and a loading factor R of 0.0044, a series of experiments were carried out and the experimental results agree well with the theoretical results. Such special designed ring electrode QCMs with approximately uniformly sensitivity distribution will provide a powerful tool for a wide range of practical applications.

References 1. Emilsson, G.; Schoch, R. L.; Feuz, L.; Höök, F.; Lim, R. Y. H.; Dahlin, A. B. ACS Applied Materials & Interfaces 2015, 7, 7505-7515. 2. Mohan, T.; Niegelhell, K.; Zarth, C. S. P.; Kargl, R.; Köstler, S.; Ribitsch, V.; Heinze, T.; Spirk, S.; Stana-Kleinschek, K. Biomacromolecules. 2014, 15, 3931–3941. 3. Vuoriluoto, M.; Orelma, H.; Johansson, L. S.; Zhu, B.; Poutanen, M.; Walther, A.; Laine, J.; Rojas, O. J. The Journal of Physical Chemistry B. 2015, 119, 15275–15286. 4. Su, J. W.; Charmchi, M.; Sun, H. W. Sci Rep. 2016, 6, 35132. 5. Mafi, R.; Pelton, R. H. Langmuir 2015, 31, 7238-7241. 6. Mazzoccoa, R.; Robinsona, B. J.; Rabotb, C.; Delamoreanuc, A.; Zenasnib, A.; Dickinsond, J. W.; Boxalld, C.; Kolosova, O. V. Thin Solid Films 2015, 585, 31-39. 7. Wu, C. L.; Li, X. M.; Song, S. Y.; Pei, Y. X.; Guo, L. L.; Pei, Z. C. Polymers 2017, 9, 482. 8. Pei, X.; Zhang, B.; Tang, J.; Liu, B.; Lai, W.; Tang, D. Anal. Chim. Acta 2013, 758, 1-18. 9. Arduini, F.; Micheli, L.; Moscone, D.; Palleschi, G.; Piermarini, S.; Ricci, F.; Volpe, G. Trends Anal. Chem. 2016, 79, 114-126. 10. Song, Y.; Shen, Y.; Chen, J.; Song, Y.; Gong, C.; Wang, L. Electrochim. Acta 2016, 211, 297-304. 11. Han, J. H.; Lee, D.; Chew, C.H.C.; Kim, T.; Pak, J. J. Sens. Actuators B Chem. 2016, 228, 36-42. 12. Chirra, H. D; Hilt, J. Z. Langmuir 2010, 26, 11249-11257. 13. Acharya, B.; Chestnut, M.; Marek, A.; Smirnov, A. I.; Krim, J. Tribology Letters, 2017, 65, 115. 14. Guo, Y. B.; Wang, D. G.; Yang, L.; Liu, S. H. Polymer Surface and Interfaces 2017, 49, 543-548. 15. Iturri, J.; Vianna, A. C.; Moreno-Cencerrado, A.; Pum, D.; Sleytr, U. B.; Toca-Herrera, J. L. Beilstein J. Nanotechnol. 2017, 8, 91-98. 16. Lai, G.; Zhang, H.; Tamanna, T.; Yu, A. Anal. Chem. 2014, 86, 1789-1793. 17. Wang, M. H.; Liu, S. L,; Zhang, Y. C.; Yang, Y. Q.; Shi, Y.; He, L. H.; Fang, S. M.; Zhang, Z. H. Sensors and Actuators B-Chemical 2014, 203, 497-503. 18. Wu, Y.; Xue, P.; Kang, Y.; Hui, K.M. Anal. Chem. 2013, 85, 3166-3173. 19. Zhang, S. L.; Bai, H. H.; Pi, J.; Yang, P. H.; Cai, J. Y. Anal. Chem. 2015, 9, 4797-4805. 20. Kovar, D.; Farka, Z.; Skladal, P., Anal. Chem. 2014, 17, 8680-8686. 21. Tan, L.; Lin, P. L.; Chisti, M. M.; Rehman, A.; Zeng, X. Q. Anal. Chem. 2013, 18, 8543-8551. 22. Fabien, J.; Youbok, L.; Stephen, J. M.; Richard, W. C. Anal. Chem. 1998, 70, 237-247. 6


Page 6 of 8

Page 7 of 8 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


23. Gao, J. Y.; Huang, X. H.; Wang, Y. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 2013, 9, 1883–1886. 24. Ward, M. D.; Delawski, E. J. Anal. Chem. 1991, 63, 886–890. 25. Oltra, R.; Efimov, I. O. Rev. Sci. Instrum. 1995, 66, 1136–1141. 26. Hillier, A. C.; Ward, M. D. Anal. Chem. 1992, 64, 2539–2554. 27. Kawaski, T.; Mochida, T.; Katada, J.; Okahata, Y. Anal. Sci. 2009, 25, 1069–1075. 28. Huang, X. H.; Bai, Q. S.; Hu, J. G.; Hou, D. Sensors 2013, 17, 1785.

29. Bottom, V. E. Introduction to Quartz Crystal Unit Design; New York: Van Nostrand Reinhold, 1982.

7



For Table of Contents Only

8


Page 8 of 8

Quartz Crystal Microbalance with approximately uniformly sensitivity

Recommend Documents