Mold-Free Manufacturing of Highly Sensitive And Fast Response Pressure Sensors Through High-Resolution 3d Printing And Conformal Oxidative Chemical Vapor Deposition Polymers.

In this work, w e showcase a new manufacturing paradigm to exclude conventional mold-dependent manufacturing of pressure sensors, which typically requires a series of complex and expensive patterning processes. Our mold-free manufacturing leverages high-resolution 3D printed multiscale microstructures as substrate and a gas-phase conformal polymer coating technique to complete the mold-free sensing platform. The array of dome and spike structures with a controlled spike density of a 3D-printed substrate ensures a large contact surface with pressures applied and extended linearity in a wider pressure range. For uniform coating of sensing elements on the microstructured surface, oxidative chemical vapor deposition is employed to deposit a highly conformal and conductive sensing element, poly(3,4-ethylenedioxythiophene) at low temperatures (< 60 °C). The fabricated pressure sensor reacts sensitively to various ranges of pressures (up to 185 kPa -1 ) depending on the density of the multiscale features and shows an ultra-fast response time (∼36 μs). The mechanism investigations through the finite element analysis identify the effect of the multiscale structure on the figure-of-merit sensing performance. Our unique findings are expected to be of significant relevance to the technology that requires higher sensing capability, scalability, and facile adjustment of a sensor geometry in a cost-effective manufacturing manner. This article is protected by copyright. All rights reserved.