Piezoresistive disposable weight sensor with increased sensitivity

Abstract

This study presents the design, simulation, implementation, and experimental characterization of a paperbased perforated disposable weight sensor system with a double piezoresistive layer. The demonstrated system is designed to achieve highly sensitive weight sensing operations with low-cost materials. For that purpose, the main fabrication material of the proposed disposable sensor is selected as a 289-μm-thick Strathmore 400 series Bristol paper. Approximately 48-μm-thick piezoresistive graphite paste is coated onto both sides of the paper-based cantilever beam with the aim of acquiring more sensitive weight-sensing capability. Additionally, the proposed paper-based structure has rows of closely spaced perforations at prespecified locations to facilitate the bending of the cantilever beam and to further increase the sensitivity of the system. A peripheral electronic read-out circuitry is developed and integrated into the system. It is experimentally demonstrated that the proposed weight-sensing system can measure miniature weights ranging to 2 g with a resolution of 20 mg. The implemented sensor has a sensitivity of 17.13 mV/mN or 168.01 mV/g.