摘要
Force sensing provides a crucial physical-electrical channel within sensing technology.This study showcases the fabrication and characterization of force sensors by integrating a polydimethylsiloxane(PDMS)mechanical module and an optical channel formed by two ideal InGaN/GaN light-emitting diodes(LEDs)with transmit-receive characteristics.As an emitter,the InGaN/GaN device(5 mm×4 mm)exhibits electroluminescence at 469 nm with an on-voltage of 2.33 V.As a receiver,the response spectrum of InGaN/GaN devices spans from 350 to 480 nm,featuring a peak at 390 nm,rise time of~68.4 ms,and falling edge of~61.0 ms.The PDMS film can transform the force into deformation data and influence the signals in the optical receiver.The drive current,the gap between the emitter and receiver,and distance between the LED and PDMS mechanical module all significantly influence the receiver photocurrent.Distinct from the integrated design,our PDMS-assisted force sensing model uses discrete structures to allow signal intensity optimization.The finite element simulation and experimental results indicate that force of the designed PDMS film exhibits a linear relationship with z-axis displacement and photocurrent from 0 to 0.7 mm.The findings reveal that when the PDMS film height is 1.5 mm and the distance between the emitter and receiver is near,the photocurrent is higher.Meanwhile,Ag film with a thickness of 100 nm considerably enhances the photocurrent response and signal stability in the sensing channel.Finally,a weight measurement demonstration is employed to demonstrate force sensing.The system resolution is 1.23μA/N,and the measurement range is 0 to 0.7 N.
基金
supported by the Natural Science Foundation of Jiangsu Province(BK20210593)
the National Natural Science Foundation of China(62204127,62404040)
the Fundamental Research Funds for the Central Universities(No.NS2022096).
