Enhancing Piezoresistive Pressure Response Device Sensitivity by Orders of Magnitude

Abstract A bulk material electrode interfacing approach capable of enhancing the sensitivity of piezoresistive pressure sensors with magnitude orders is presented. Metal copper microwires are emplaced between the bulk conductive substrate and an electrode connecting it to the external circuit, replacing commonly used silver paste. These microwires create gaps on the interface between the two materials and increase the initial system resistance. As the applied pressure rises, the contact area between the substrate and microwires increases while the conductive substrate deforms, resulting in overall resistance reduction. With an appropriate setting of microwires, the sensitivity of the piezoresistive pressure sensor can be enhanced up to 10⁶‐fold. The current design is widely adaptable toward different types of materials and allows a pressure operation of up to 931.2 kPa. The results indicate that rather than developing bulk materials, straightforward improvements in the device connecting interface can significantly enhance pressure response sensitivity with magnitude orders.