Design and fabrication of a LEG based stretchable piezoresistive acoustic pressure sensor for ultra low pressures

The development of an acoustic pressure sensor capable of detecting ultra-low-amplitude signals has been a crucial focus in marine, environmental, and military communication applications. This study presents the design, fabrication, and characterization of a stretchable piezoresistive acoustic pressure sensor utilizing laser-engraved graphene (LEG) technology. The sensor features a graphene-based composite sensing element encapsulated between two PDMS layers, specifically designed to operate in the ultra-low-pressure range (< 3 Pa). A calibration system based on a syringe pump was developed to evaluate the sensor's performance. Experimental results demonstrated a sensitivity of 61.00 mV/V/kPa with a maximum nonlinearity error of 0.8% FSS. Additionally, dynamic pressure measurements confirmed the sensor's capability to detect cyclic acoustic pressure variations, exhibiting a stable and repeatable response. These findings validate the feasibility of LEG-based flexible pressure sensors for detecting low-amplitude acoustic signals, offering promising potential for high-sensitivity applications in underwater noise detection, biomedical sensing, and environmental monitoring.