Ultrafast response and highly sensitivity of flexible acoustic sensor based on the controllable hierarchical Nano/Micro-Structure

Abstract

Flexible and highly sensitive acoustic sensors have become more and more essential for successful military detection. It puts a big barrier for the large-scale production and application. In this work, we have a low-cost and facile approach constructing a hierarchical nano/micro-structure based on the nanosheets of MXene (Ti3C2Tx) and the gold micro-wrinkles on polydimethylsiloxane (PDMS) surface. The period micro-wrinkles can be easily controlled by the thickness of gold layer and the pre-strain on PDMS through the uniaxial stretching method. The formed hierarchical structure can endow the high sensitivity (15 kPa−1 when applied pressure less than 50 Pa), an ultra-fast response time of 15 ms, a minimum detection of 2 Pa, which can achieve the precise acoustic detection of low frequency. Moreover, the flexible sensor also can detect the large pressure about 1000 Pa, and show stable repeatability over 1500 cycles at 400 Pa.