A Printable and Flexible Conductive Polymer Composite with Sandwich Structure for Stretchable Conductor and Strain Sensor Applications

摘要

Flexible electronics has emerged as an independent field and became increasingly popular over the past decades because of they can provide a lot of benefits compared to traditional rigid printed circuit boards, such as better durability, lighter weight, higher space efficiency, and improved comfort. Conductive polymer composites (CPCs) especially which possess flexibility and printability are very important for flexible electronics due to their capacities of offering mechanical deformation, electrical conductivity and mass production, and widely used in applications such as strain sensor, stretchable conductor and e-skin, etc. High sensitivity, high electrical conductivity and cycling stability are required for the strain sensor in practical applications. Up to now, development of the strain sensors combination with highly electrical conductivity, high stretchability, high sensitivity, simple fabrication process and low-cost is still a great challenge. Herein, we develop a facile and low-cost method to fabricate large-area printable CPCs, which embedded in two thin polydimethylsiloxane (PDMS) layers forming a sandwich structure. The CPCs were prepared by mixing the core-shell structures conductive fillers (silver nanoparticles coated on polystyrene microspheres) with a liquid PDMS followed by a heat curing. The sandwich structured CPCs exhibit good electrical conductivity even though under intense mechanical deformations such as bending, curling and stretching, which have promising potential in flexible electrodes. Moreover, the sandwich structured CPCs can be used as strain sensor, and show a high sensitivity of 17.5 in strain of 0%-10%, 6.0 in strain of 10%-60% and that of 78.6 in strain of 60%-80%. The sensing performance of the as-prepared sandwich structured CPCs in controlling the rotation speed of a personal computer (PC) fan are further demonstrated.