Copper-Electroplating of Biodegradable PCL Nanofiber Mats

Abstract

In this study, biodegradable polycaprolactone (PCL) nanofibers were copper (Cu) electroplated in a more environmentally friendly bath compared to conventional electroplating baths. The Cu-plating mechanism and determination of the optimum parameters for the production of Cu-plated PCL nanofiber mats were explained. PCL nanofibers were produced on metal frames by electrospinning. Cu-electroplating needs a conductive surface. To provide this, a gold/palladium mixing was sputtered on the PCL samples with different sputtering thicknesses. After determining the minimum sputtering thickness, the samples were Cu-plated for 1,3,5 and 30 minutes in the electroplating bath. Surface properties of the samples were evaluated after nanofiber production, Au/Pd sputtering and electroplating, respectively. Elemental analyses, mapping and electrical characterizations were also performed after electroplating. The Cu-coated areas gave a sheet resistance in the range of milliohms indicating a highly conductive structure. Every step of the study is described in detail to provide insight for further studies.

Keywords

• Nanofiber
• Electrospinning
• Biodegradable Electronics
• Copper Electroplating
• Electrical Characterization

References

1. 1. Irimia-Vladu M, Głowacki ED, Voss G, Bauer S, Sariciftci NS 2012 Green and biodegradable electronics Mater Today. 15(7–8):340–6.
2. 2. Irimia-Vladu M “Green” electronics: biodegradable and biocompatible materials and devices for sustainable future 2013 Chem. Soc. Rev. 43(2):588–610.
3. 3. Tan MJ, Owh C, Chee PL, Kyaw AKK, Kai D, Loh XJ 2016 Biodegradable electronics: cornerstone for sustainable electronics and transient applications. J Mater Chem C. 4(24):5531–58.
4. 4. Abdulrhman M, Zhakeyev A, Fernández-Posada CM, Melchels FPW, Marques-Hueso J 2022 Routes towards manufacturing biodegradable electronics with polycaprolactone (PCL) via direct light writing and electroless plating. Flex Print Electron 7(2):025006
5. 5. Frenot A, Chronakis IS 2003 Polymer nanofibers assembled by electrospinning Current Opinion in Colloid and Interface Science 8: 64–75.
6. 6. Li D, Xia Y 2004 Electrospinning of Nanofibers: Reinventing the Wheel? Adv Mater 16(14):1151–70
7. 7. Greiner A, Wendorff JH. Electrospinning: A Fascinating Method for the Preparation of Ultrathin Fibers 2007 Angew Chemie Int Ed 46(30):5670–703.
8. 8. Agarwal S, Greiner A, Wendorff JH 2013 Functional materials by electrospinning of polymers. Prog Polym Sci. 38(6):963–91.

9. 9. Blachowicz T, Ehrmann A 2020 Conductive Electrospun Nanofiber Mats. Mater 2020, 13(1):152.
10. 10. Junger IJ, Wehlage D, Böttjer R, Grothe T, Juhász L, Grassmann C, et al. 2018 Dye-Sensitized Solar Cells with Electrospun Nanofiber Mat-Based Counter Electrodes. Mater 11(9):1604.
11. 11. Li Z, Lin Z, Han M, Mu Y, Yu J 2021 Electrospun carbon nanofiber-based flexible films for electric heating elements with adjustable resistance, ultrafast heating rate, and high infrared emissivity. J Mater Sci 56(26):14542–55.
12. 12. Wang Y, Yokota T, Someya T 2021 Electrospun nanofiber-based soft electronics. NPG Asia Mater 13(1):1–22.
13. 13. Yang G, Tang X, Zhao G, Li Y, Ma C, Zhuang X, et al. 2022 Highly sensitive, direction-aware, and transparent strain sensor based on oriented electrospun nanofibers for wearable electronic applications. Chem Eng J. 435:135004.
14. 14. Graham A 1971 Electroplating Engineering Handbook, 3rd Edition. New York: Van Nostrand Company
15. 15. Schlesinger M, Paunovic M 2010 Modern Electroplating, 5th Edition. John Wiley & Sons.
16. 16. Sinha-Ray S, Zhang Y, Yarin AL 2011 Thorny Devil Nanotextured Fibers: The Way to Cooling Rates on the Order of 1 kW/cm2. Langmuir 27(1):215–26.
17. 17. An S, Jo HS, Al-Deyab SS, Yarin AL, Yoon SS 2016 Nano-textured copper oxide nanofibers for efficient air cooling. J Appl Phys 119(6):065306.
18. 18. An S, Jo HS, Kim DY, Lee HJ, Ju BK, Al-Deyab SS, et al. 2016 Self-Junctioned Copper Nanofiber Transparent Flexible Conducting Film via Electrospinning and Electroplating. Adv Mater 28(33):7149–54.
19. 19. An S, Kim Y Il, Jo HS, Kim MW, Lee MW, Yarin AL, et al. 2017 Silver-decorated and palladium-coated copper-electroplated fibers derived from electrospun polymer nanofibers. Chem Eng J. 327:336–42.
20. 20. An S, Kim Y Il, Jo HS, Kim MW, Swihart MT, Yarin AL, et al. 2018 Oxidation-resistant metallized nanofibers as transparent conducting films and heaters. Acta Mater. 143:174–80.
21. 21. An S, Lee C, Liou M, Jo HS, Park JJ, Yarin AL, et al. 2014 Supersonically blown ultrathin thorny devil nanofibers for efficient air cooling. ACS Appl Mater Interfaces 6(16):13657–66.
22. 22. Huh JW, Jeon HJ, Ahn CW 2017 Flexible transparent electrodes made of core-shell-structured carbon/metal hybrid nanofiber mesh films fabricated via electrospinning and electroplating. Curr Appl Phys. 17(11):1401–8.
23. 23. Ebadi SV, Fashandi H, Semnani D, Rezaei B, Fakhrali A 2020 Overcoming the potential drop in conducting polymer artificial muscles through metallization of electrospun nanofibers by electroplating process. Smart Mater Struct 29(8):085036.
24. 24. Shaw J, Huntington N, Romolo J 1972 Copper electroplating in a citric acid bath, Patent No: US3684666A