Ballistic graphene arrays for ultra-high pressure sensing

Abstract

Atomically thin two-dimensional materials, such as graphene, exhibit extreme high-pressure sensitivity compared to the commercially used pressure sensors due to their high surface-to-volume ratio and excellent mechanical properties. The smaller piezoresistance of graphene across different transport regimes limits its pressure sensitivity compared to other two-dimensional materials. Using membrane theory and the thin-film adhesivity model, we show miniaturization as a means to enhance the overall performance of graphene pressure sensors. Our findings reveal that ballistic graphene can be configured to measure ultra-high pressure (≈109 Pa) with many-fold high-pressure sensitivity than other contemporary two-dimensional materials. Based on these findings, we propose an array of ballistic graphene sensors with extreme high-pressure sensitivity and ultra-high-pressure range that will find applications in next-generation nano-electro-mechanical system pressure sensors. The performance parameters of the array sensors can be further enhanced by reducing the size of graphene membranes and increasing the number of sensors in the array. The methodology developed in this paper can be used to explore similar applications using other two-dimensional materials.