Realization of motion sensing composites prepared from the incorporation of three-dimensional porous conductive foams and polydimethylsiloxane

This study has effectively integrated polydimethylsiloxane (PDMS) elastomer and three-dimensional (3D) porous conductive foams (CFs) to fabricate functional (CF-PDMS) composites containing conductive networks via a low-cost, facile and simultaneous freeze-dry-covering method, which possess both broad stretching and sensing ranges, using as flexible and wearable sensors (CF-PDMS sensors) for detecting and monitoring human motions. Specifically, the 3D porous CF with cellular structures is prepared by combining low-cost polymers (gelatin/chitosan) and carbon-based fillers (graphene oxide-carbon nanotubes), which are then crosslinked with a cross-linker agent (glutaraldehyde) and simply freeze-dried to produce a promising foam with a cellular structure with conductive bridges. The effective incorporation of carbon-based fillers and the biopolymer matrix to fabricate a functional composite with a cellular structure, i.e., the 3D porous CF, is demonstrated in terms of its morphological, chemical, crystalline, and thermal properties. Afterward, the constructed networks of the 3D porous CF are well covered by an elastomeric mixture of PDMS liquid and curing agent (10:1) to produce CF-PDMS composites with good stretchability and sensing performance. The sensing performance results show that these composite sensors exhibit good resistance signals under various mechanical deformations, demonstrating their outstanding stability and repeatability. Because the monitoring of various movements of human joints using wearable electronics has wide-range applications in human motion detection, these findings are of great significance. Concomitantly, the composite sensors are also used for creating a portable device with motion detection wireless via a smartphone (i.e., an integration of a Bluetooth module and an Arduino assistant). These approaches can provide a promising strategy for developing wearable sensors regarding the connections of real objects to the Internet from the Internet of Things (IoT) in the future. •Composites with 3D porous conductive foam-inspired cellular structure and flexible PDMS matrix were fabricated.•The composites possessed high conductivity with significantly enhanced mechanical properties.•The composites were well applied for monitoring human motions with a Bluetooth module.•High sensitivity in a wide-stretching range and good stability were obtained.