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 isdesigned to achieve highly sensitive weight sensing operations with low-cost materials. For that purpose, the mainfabrication 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 beamwith the aim of acquiring more sensitive weight-sensing capability. Additionally, the proposed paper-based structurehas rows of closely spaced perforations at prespecified locations to facilitate the bending of the cantilever beam and tofurther increase the sensitivity of the system. A peripheral electronic read-out circuitry is developed and integrated intothe system. It is experimentally demonstrated that the proposed weight-sensing system can measure miniature weightsranging 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.