A Flexible Integrated Bending Strain and Pressure Sensor System for Motion Monitoring.

Rou Feng,Yifeng Mu,Yuxuan Liu,Xijun Jiang,Xiangwen Zeng,Qibei Gong,Weijie Jia,Youfan Hu

doi:10.3390/s21123969

Rou Feng, Yifeng Mu + Show 6 more

Open Access

https://doi.org/10.3390/s21123969

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Abstract

Flexible sensors have attracted increasing research interest due to their broad application potential in the fields of human–computer interaction, medical care, sports monitoring, etc. Constructing an integrated sensor system with high performance and being capable of discriminating different stimuli remains a challenge. Here, we proposed a flexible integrated sensor system for motion monitoring that can measure bending strain and pressure independently with a low-cost and simple fabrication process. The resistive bending strain sensor in the system is fabricated by sintering polyimide (PI), demonstrating a gauge factor of 9.54 and good mechanical stability, while the resistive pressure sensor is constructed based on a composite structure of silver nanowires (AgNWs) and polydimethylsiloxane (PDMS)-expandable microspheres with a tunable sensitivity and working range. Action recognition is demonstrated by attaching the flexible integrated sensor system on the wrist with independent strain and pressure information recorded from corresponding sensors. It shows a great application potential in motion monitoring and intelligent human–machine interfaces.

Highlights

Flexible sensor systems have been widely explored with applications in intelligent robotics [1,2,3,4], electronic skin [5,6,7,8], wearable electronic [9,10,11], etc., because of their superiority in portability and conformability for a better human–computer interface
In the past few years, it has been well demonstrated that physiological information of the human body, such as pulse [12,13], blood pressure [14], body temperature [15,16], electrocardiogram [17], etc., and the mechanical status of the human body, including movements and postures [18,19], can be monitored by flexible sensor systems when they are properly attached to different areas on the human body, providing valuable data for health and sports status assessments and clinical diagnosis
The integrated system consists of two functional modules, a bending strain sensor which is based on graphite wires with a serpentine structure that sintered from polyimide (PI), and a pressure sensor which is based on a composite structure of polydimethylsiloxane (PDMS)-expandable microspheres and silver nanowires

Summary

Introduction

Flexible sensor systems have been widely explored with applications in intelligent robotics [1,2,3,4], electronic skin [5,6,7,8], wearable electronic [9,10,11], etc., because of their superiority in portability and conformability for a better human–computer interface. The calculated gauge factor, GF of these devices decreased from 9.54 to 3.5 as the length of the wire increased from 122 mm to 146 mm, while it showed no obvious dependence on the width of the wire when it doubled from 1.0 mm to 2.0 mm This different dependence on the two geometry factors comes from the working mechanism of the sensor, which is based on the resistance change induced by the relative displacement of flakes in the graph‐. The ca gauge factor, GF of these devices decreased from 9.54 to 3.5 as the leng wire increased from 122 mm to 146 mm, while it showed no obvious dependenc width of the wire when it doubled from 1.0 mm to 2.0 mm This different depend the two geometry factors comes from the working mechanism of the sensor, based on the resistance change induced by the relative displacement of flakes in th ite under deformation [26].

Crosstalk between Different Sensors in the Integrated System

Demonstration of Motion Monitoring

Findings

Conclusions