A Fabric-Based Strain Sensor with a Microbridge Structure and the Supercapacitor-Powered Integrated Sensing System

Area of Science:

• Materials Science
• Nanotechnology
• Wearable Electronics

Background:

• Fabric-based strain sensors are crucial for wearable electronics, demanding high sensitivity and stability.
• Existing sensors often face limitations in performance and durability.

Purpose of the Study:

• To develop highly sensitive and stable fabric strain sensors using a novel microbridge structure.
• To integrate these sensors with microsupercapacitors for a self-powered wearable sensing system.

Main Methods:

• Coating thermoplastic polyurethane (TPU) fabric with carbon nanotubes (CNTs) and polypyrrole (PPy).
• Designing a microbridge structure where CNTs bridge stretching-induced cracks in the TPU-CNT-PPy fabric.
• Fabricating microsupercapacitors (MSCs) using the TPU-CNT-PPy material.

Main Results:

• The TPU-CNT-PPy strain sensors exhibited high sensitivity (GF = 231.5) over a 150% working range with fast response (166 ms) and recovery (195 ms).
• The microbridge structure significantly improved electrical resilience, enhancing sensor stability.
• TPU-CNT-PPy-based MSCs demonstrated high specific capacitance (460.3 mF cm⁻²) and excellent cycling stability (96.69% retention over 10,000 cycles).

Conclusions:

• The microbridge strategy effectively enhances strain sensor performance for wearable applications.
• An integrated sensing system combining strain sensors and MSCs was successfully demonstrated, with sensor signals detectable via Bluetooth.
• This work provides a viable approach for advanced wearable electronic systems.