A flexible strain sensor with high adhesion and mechanical enhancement based on PDMS/MWCNTs

With the rapid advancement of flexible electronic technology, flexible sensors have demonstrated significant application potential in the fields of electronic skin and wearable health monitoring. However, their widespread application is still limited by challenges including poor substrate adhesion, insufficient mechanical strength, and inadequate conductive layer stability. To address the weak interfacial adhesion and pronounced signal hysteresis of PDMS, this study modified it via the incorporation of PEG-PPG-PEG and ANF. This modification enhanced the elastomer’s adhesiveness and mechanical properties, while also reducing signal hysteresis. Hydroxylated MWCNTs were chosen as the conductive material, and a MWCNTs conductive layer was fabricated via vacuum filtration. Encapsulation with a double layer of A 1 -P 6 -PDMS result in a sandwich-structured conductive film A 1 -P 6 -PDMS/MWCNTs/A 1 -P 6 -PDMS, greatly improving the sensor's cyclic stability and durability. Experimental results indicate that the sensor exhibits high elongation at break (>140 %), strong adhesion (capable of stably holding a 20 g weight), high tensile strength (>2.5 MPa), fast response time (52 ms) and high sensitivity (GF = 27.63). It can accurately monitor physiological signals such as human joint movements, offering a promising method for the widespread application of electronic skin.