Characterization of Microstructured Multiwalled Carbon Nanotube/Polydimethylsiloxane Composites for Piezoresistive Sensing Applications

Abstract

Technological advancements in the field of flexible and printed electronics are creating a need for large‐area sensors that can be embedded over different types of surfaces. Such sensors can be used to monitor physical signals over flexible, curved, or soft devices. Hence, it is herein proposed, a formulation to produce piezoresistive MWCNT/PDMS composites with tunable electric properties for pressure sensing purposes. The composite is obtained through few manufacturing steps, avoiding the use of hazardous solvents. Different weight percentages of MWCNT dispersed in PDMS are evaluated and results evidence that using 3.0 wt% of infill is enough to obtain highly sensitive sensors. To enhance the dispersion of the MWCNT and add microstructure to the composite, a system composed of a surfactant and foaming agent is used. Finally, pressure sensing units and arrays are printed and tested. The sensors present fast response, low hysteresis, repeatability, and a sensing range of 0 kPa – 160 kPa. The composite is more sensitive to lower pressure and a maximum sensitivity of 8.0 %.kPa‐1 was achieved for porous composites for pressure < 10 kPa. Thanks to these characteristics, the sensors were successfully used in the development of a pressure‐sensing array and heartbeat sensor for proof‐of‐concept.This article is protected by copyright. All rights reserved.