Highly Uniform and Low Hysteresis Piezoresistive Pressure Sensors Based on Chemical Grafting of Polypyrrole on Elastomer Template with Uniform Pore Size. Issue 33 (13th June 2019)

• Record Type: Journal Article
• Authors: Oh, Jinwon; Kim, Jin‐Oh; Kim, Yunjoo; Choi, Han Byul; Yang, Jun Chang; Lee, Serin; Pyatykh, Mikhail; Kim, Jung; Sim, Joo Yong; Park, Steve
• Is Part Of: Small. Volume 15:Issue 33(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-13
• Subjects: chemical grafting -- high uniformity -- low hysteresis -- microfluidics -- pressure sensors; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201901744
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Sensor‐to‐sensor variability and high hysteresis of composite‐based piezoresistive pressure sensors are two critical issues that need to be solved to enable their practical applicability. In this work, a piezoresistive pressure sensor composed of an elastomer template with uniformly sized and arranged pores, and a chemically grafted conductive polymer film on the surface of the pores is presented. Compared to sensors composed of randomly sized pores, which had a coefficient of variation (CV) in relative resistance change of 69.65%, our sensors exhibit much higher uniformity with a CV of 2.43%. This result is corroborated with finite element simulation, which confirms that with increasing pore size variability, the variability in sensor characteristics also increases. Furthermore, our devices exhibit negligible hysteresis (degree of hysteresis: 2%), owing to the strong chemical bonding between the conductive polymer and the elastomer template, which prevents their relative sliding and displacement, and the porosity of the elastomer that enhances elastic behavior. Such features of the sensor render it highly feasible for various practical applications in the near future. Abstract : Piezoresistive sensors with high uniformity and low hysteresis are fabricated via chemically grafting a conductive polymer on the surface of an elastomer template with uniform pore size and arrangement. Finite element analysis confirms the importance of pore size uniformity in sensor uniformity.