Ethanol-assisted room-temperature rapid self-healing polydimethylsiloxane-polyurea/carbon composite elastomers for energy harvesters and smart sensors

Self-healing materials are widely used in flexible and stretchable electronic devices because of their capability to repair cracks or damages that occur during usage, thus extending their lifetime. In this work, self-healable polydimethylsiloxane-polyurea/carbon composite elastomers (CCF/PDMS) are prepared successfully via the design of multiple hydrogen bonds. The multiple hydrogen bonds formed between the urea groups of polymer chains and between the urea groups and the carboxyl/hydroxyl groups of the graphite/carboxylated carbon nanotube complex fillers (CCFs) endow CCF/PDMS with excellent recyclability, mechanical properties (687.9%, 1.02 MPa), and rapid ethanol-assisted self-healing properties (99.4% at room temperature for 3 h), which exceeds most of the reported polydimethylsiloxane-based composites. Besides, the mechanism of ethanol-assisted self-healing properties is investigated using in situ FTIR spectra, providing a new strategy for self-healing composites of hydrogen bonding systems. Significantly, CCF endows CCF/PDMS with impressive self-powered capability. The self-healing triboelectric nanogenerator (SH-TENG) with an area of 30 x 30 x 0.25 mm3 prepared from CCF/PDMS has a remarkable output (125 V, 11.9 mu A) and can easily power 144 LEDs. The design strategy with excellent mechanical performance, ultrahigh self-healing properties, and remarkable self-powered capability can meet the wide applications of wearable flexible sensors, electronic skins, flexible robots, self-powered devices, etc. Multiple H-bond networks and unique structures are designed in CCF/PDMS. This CCF/PDMS elastomer simultaneously exhibits excellent tensile, self-healing, and triboelectric properties, promising to be used in energy harvesters and motion sensors, etc.