A Stretchable and Tough Conductive Elastic Film for Multifunctional Flexible Strain Gauges

As an important branch of modern science and technology, flexible sensor combines the functions of traditional sensors with the characteristics of flexible materials to meet the needs of modern electronic devices for lightweight, flexible and wearable characteristics. However, flexible sensors are faced with problems such as poor stability and weak anti-interference ability in extreme environments. Here, a strategy of combining thermoplastic polyurethane and conductive carbon black is adopted to obtain conductive elastic film with good conductivity and excellent mechanical properties (TPU@CB film). TPU@CB film exhibits very good mechanical strength (8 MPa). When TPU@CB film is assembled into a sensor, it exhibits wide detection range (600%), low detection limit (0.05%) and short response time (15 ms). Notably, the TPU@CB film demonstrates clear detection capabilities for both ECG and EMG signals of the human body when utilized as an electrode patch. Thanks to lithography, TPU@CB film is machined into strain gauge shape. TPU@CB strain gauge achieves a high signal-to-noise ratio and can detect a wide range of frequency vibrations from 0 to 900 Hz, as well as accurately detect the speed of the motor. This provides a feasible way to promote the development of flexible electronics.