Flexible and bio-compatible temperature sensors based on carbon nanotube composites

Flexible temperature sensors are desired for a wide range of applications in engineering, biology, and medicine. In the present paper, we describe the development of novel flexible temperature sensors based on carbon nanotube (CNT) forest composites, and we demonstrate their ability to sense on-skin temperatures. The fabrication process of these sensors is simple and they demonstrate bio-compatibility, high performance, and a simple sensing scheme. When subjected to high temperatures, the CNTs are strained due to the thermal mismatch between the CNT forest and the matrix, which modifies their electrical resistance in a stable and reproducible temperature–resistance relationship. The sensors demonstrate sensitivities of ~0.1Ω/°C or higher, and show stable Young's modulus of ~0.1MPa for temperatures below 100 °C. These sensors, thus, pave the way toward a new generation of flexible, wearable, and bio-compatible temperature sensors, which can be used as flexible lab-on-a-chip devices or as a sensory artificial skin.