Carbon nanotube/liquid metal hybrid coating-based flexible pressure piezoresistive sensors

Abstract

This work prepared carbon nanotubes/liquid metal (CNT/LM) coating films on a PDMS/Ecoflex (PE) blend substrate with a proportion of 2:1. An ultraviolet laser was used to improve the bonding between CNT/LM and PE 2:1, resulting in the formation of a robust and innovative conductive layer. The interaction between CNT and LM droplets, coupled with laser treatment on the CNT/LM coating, led to a reduced liquid metal oxide layer. The CNT/LM solution demonstrated highly stable CNTs particles with the assistance of liquid metal. The result demonstrated that CNT-assisted liquid metal could improve the electrical resistance compared to the CNT-only layer. Furthermore, the PE/CNT/LM/PE fabricated sensor exhibited enhanced sensitivity and recoverability under lower and higher applied compressive strains with a gauge factor ranging from 20.6 (10 %) to 57 (30 %) and a relatively fast response time (70 ms). The PE/CNT/LM/PE sensor showed extremely high load-bearing capacity confirming the potential of PE 2:1 to bear the load without disrupting the electrical signal. The electromechanical properties confirmed the potential of PE/CNT/LM/PE in wearable electronics and various sensing characteristics.