Highly Sensitive Piezoresistive Sensors Based on a Voltage Divider Circuit With TFTs for Ultra-Low Pressure Detection

Jiayu Feng,Longlong Chen,Jianhua Zhang,Xifeng Li

doi:10.1109/jeds.2021.3085135

Jiayu Feng, Longlong Chen + Show 2 more

Open Access

https://doi.org/10.1109/jeds.2021.3085135

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Abstract

A highly sensitive piezoresistive tactile sensor combined with the thin-film transistors (TFTs) is produced in this letter. The sensor uses two-dimensional Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -MXenes as piezoresistive material which is one type of transition metal carbide, nitride and/or carbonitride with a lamellar structure. A voltage divider circuit is designed by connecting piezoresistive material with TFT technology. TFT works in the subthreshold and saturation region during the sensing process to ensure that the magnitude change of current is measured in a small voltage range. The tactile sensor shows high sensitivity of 4636.1 kPa $^{-1}$ , ultra-low tactile detection of 0.98 Pa, and extremely durability for 1,500 sensing cycles. Resultantly, the sensor demonstrates excellent potential for electronic touchscreens and advanced medical testing.

Highlights

As human beings gradually enter the intelligent society, sensors will be widely used in many fields, such as human-machine interface, on-line medical care, intelligent skin and so on [1]–[3]
It approves that the gate voltage and the source-drain current are used as the basic sensor signals extracted from the Thin film transistors (TFTs) [16]
The source and drain electrodes of the TFT are connected to the probes of Keithey 4200

Summary

INTRODUCTION

As human beings gradually enter the intelligent society, sensors will be widely used in many fields, such as human-machine interface, on-line medical care, intelligent skin and so on [1]–[3]. Thin film transistors (TFTs) technology has been successfully used in large-scale integration, such as display panels [14], sensor devices [15] and so on, owing to its advantages of small-size, low-cost and amplification effect. It approves that the gate voltage and the source-drain current are used as the basic sensor signals extracted from the TFTs [16]. The change of current measured by a separate voltage divider without TFT is not obviously enough to be subdivided [17] It is hard for the device without TFT to detect the pressure which is loaded in a small range. A semiconductor parameter analyzer (4200-SCS, Keithley) was used to record transfer characteristics of TFT and the performance of the sensor

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSION