In-situ sugar-templated porous elastomer sensor with high sensitivity for wearables

Abstract

Fabrication of elastic pressure sensors with low cost, high sensitivity, and mechanical durability is important for wearables, electronic skins and soft robotics. Here, we develop high-sensitivity porous elastomeric sensors for piezoresistive and capacitive pressure detection. Specifically, a porous polydimethylsiloxane (PDMS) sponge embedded with conductive fillers of carbon nanotubes (CNTs) or reduced graphene oxide (rGO) was fabricated by an in-situ sugar template strategy. The sensor demonstrates sensitive deformation to applied pressure, exhibiting large and fast response in resistance or capacitance for detection of a wide range of pressure (0‒5 kPa). PDMS, as a high-elasticity framework, enables creation of sensors with high sensitivity, excellent stability, and durability for long-term usage. The highest sensitivities of 22.1 and 68.3 kPa⁻¹ can be attained by devices with 5% CNTs and 4% rGO, respectively. The geometrics of the sponge sensor is tailorable using tableting technology for different applications. The sensors demonstrate finger motion detection and heart-rate monitoring in real-time, as well as a capacitive sensor array for identification of pressure and shape of placed objects, exhibiting good potential for wearables and human-machine interactions.

Graphical abstract

Keywords

porous elastomer / sugar template / wearable pressure sensor / graphene / carbon nanotube

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