Flexible Microfluidic Strain Sensor Made with Poly(3,4-ethylenedioxythiophene):polystyrenesulfonate–MXene–Au Nanocomposites for Monitoring Physiological Signals

Flexible strain sensors have been widely used in wearable electronics. However, the fabrication of flexible strain sensors with a large strain detection range, high sensitivity, and negligible hysteresis remains a formidable challenge, even after enormous advancements in the field. Herein, a flexible microfluidic strain sensor was fabricated by filling poly(3,4-ethylenedioxythiophene):polystyrenesulfonate-MXene-gold (PEDOT:PSS-MXene-Au) nanocomposites into microchannels in an elastic matrix. Owing to the unique properties of the nanofiller and Ecoflex elastomer microchannel, the microfluidic strain sensor detected a strain of 0%-500% with low hysteresis (2.4%), high sensitivity (guage factor = 25.4), short response times (∼86 ms), and good durability. Moreover, the flexible microfluidic sensor was used to detect various physiological signals and human activities, control a mechanical hand, and capture hand motions in real time. As demonstrated by its good performance, the proposed flexible microfluidic sensor holds great potential in applications such as wearable electronics, physiological signal monitoring and human-machine interactions.