3D Single‐Layer‐Dominated Graphene Foam for High‐Resolution Strain Sensing and Self‐Monitoring Shape Memory Composite

Abstract

Flexible intelligent materials are desired to effectively regulate their own deformation and accurately sense their immediate morphology at the same time. Graphene foam is an attractive material for strain sensing and electrical/thermal performance control due to its outstanding mechanical, electrical, and thermal properties. However, graphene‐foam‐based materials with both strain sensing and deformation control capabilities are rarely reported. Here, a multiscale design of graphene foam with a single‐layer‐graphene‐dominated microstructure and resilient 3D network architecture, which leads to exceptional strain sensing performance as well as modulation ability of the electrical and thermal conductivity for shape memory polymers, is reported. The graphene foams exhibit a strain detection limit of 0.033%, a rapid response of 53 ms, long‐term stability over 10 000 cycles, significant thermoacoustic effect, and great heat‐generation and heat‐diffusion ability. By combining these advantages, an electro‐activated shape‐memory composite that is capable of monitoring its own shape state during its morphing process, is demonstrated.

Tailoring the supramolecular interaction of ionic liquids for high-sensitivity temperature monitoring under high pressure

“…1e, the sensitivity increases with the higher concentration of iron ions, and the sensitivity also significantly improves with temperature elevation. The ionic liquid containing 400 mg mL −1 FeCl 3 exhibits an impressive sensitivity of up to 30.65%/°C, surpassing the reported values of traditional temperature-sensitive materials 16–36 (Fig. 1f) and much higher than that of PT100 (0.278%/°C), which is commonly used for high-precision temperature monitoring.…”

“…1 Therefore, developing temperature sensors with high precision and environmental adaptability remains a signicant challenge. A variety of inorganic and organic temperature-sensitive conductive materials have been developed for resistive temperature sensors, including metals (gold, 16 silver, 17 and chromium 18 ), MXenes, 19 carbon materials (carbon nanotubes, 20 graphene, 21,23 graphite, 22 and carbon black nanoparticles 24 ), conductive polymers, 25,26 ionic hydrogels, [27][28][29][30] ionogels, [31][32][33][34][35] ionic liquids, 36 and commercial PT100. Among these materials, ionic liquids exhibit excellent potential for temperatureresponsive applications.…”

Multispecies-Coadsorption-Induced Rapid Preparation of Graphene Glass Fiber Fabric and Applications in Flexible Pressure Sensor Based on the Hierarchical Conductive Configuration

“…4c, the sensor was attached on the wrist for detecting real-time pulse signals. Repeatable and regular pulse shapes were detected under the relaxation conditions, and the ΔR/R 0 could reach ~ 40%, which is higher than most of the state-of-the-art sensors [50][51][52][53] . Furthermore, each pulse peak clearly displays the typical features of the pulse waveform, i.e., percussion wave (P-wave), tidal wave (T-wave), and diastolic wave (D-wave) (inset in Fig.…”

Electrically and Thermally Triggered Three-Dimensional Graphene-Foam-Reinforced Shape Memory Epoxy Composites

“…Figure 1c shows the Raman measurement of pristine GrF, displaying three major characteristic signatures, including sp 2 carbon-carbon bonds' in-plane vibrations (G band), out-of-plane vibrations due to structural defects (D band), and second disorder band (2D band). The D peak's significant low intensity compared with the G peak indicates that the graphene sheets are primarily defect-free [43][44][45][46][47][48][49][50][51][52]. The D and 2D peaks of pristine GrF are found at 1315.64 and 2704.35 cm −1 , respectively.…”

“…Shivakumar et al demonstrated that incorporating 0.1 vol.% of GrF into SMP epoxy increased thermal conductivity by 62%, thereby accelerating the SME [40]. Additionally, Rong et al established the electro-activation of SME in SMPs through single-layer GrF [46].…”