Highly Stretchable and Sensitive Multimodal Tactile Sensor Based on Conductive Rubber Composites to Monitor Pressure and Temperature

Abstract

Stretchable and flexible tactile sensors have been extensively investigated for a variety of applications due to their outstanding sensitivity, flexibility, and biocompatibility compared with conventional tactile sensors. However, implementing stretchable multimodal sensors with high performance is still a challenge. In this study, a stretchable multimodal tactile sensor based on conductive rubber composites was fabricated. Because of the pressure-sensitive and temperature-sensitive effects of the conductive rubber composites, the developed sensor can simultaneously measure pressure and temperature, and the sensor presented high sensitivity (0.01171 kPa−1 and 2.46–30.56%/°C) over a wide sensing range (0–110 kPa and 30–90 °C). The sensor also exhibited outstanding performance in terms of processability, stretchability, and repeatability. Furthermore, the fabricated stretchable multimodal tactile sensor did not require complex signal processing or a transmission circuit system. The strategy for stacking and layering conductive rubber composites of this work may supply a new idea for building multifunctional sensor-based electronics.

Recent Advancements in Physiological, Biochemical, and Multimodal Sensors Based on Flexible Substrates: Strategies, Technologies, and Integrations

“…With the development of science and technology, the demand for integration and miniaturization is increasing, so multimodal sensors have emerged Table summarizes the performance parameters of the most recent multimodal sensors. ,,,,,,,,,− Multimodal biochemical sensors are partially described in Tables –, so only some of the multimodal biochemical sensors are listed in Table . The table shows that multimodal sensors are integrated with two or more sensors on the same substrate to achieve multifunctional measurements.…”

Progress in Microtopography Optimization of Polymers-Based Pressure/Strain Sensors

“…Polydimethylsiloxane (PDMS), as a kind of silicone elastomer that has proven to be a promising substrate due to its great stretchability, high thermal stability, chemical stability, simple processing, low price, etc. [ 44 , 45 , 46 ]. Due to its thinness, breathability, and excellent biocompatibility, it can be directly attached to human skin without causing allergic reactions or used as a flexible tissue-engineering material implanted in the body [ 47 , 48 , 49 ].…”

Conducting Polymers for the Design of Tactile Sensors

“…A flexible capacitive tactile sensor was proposed for multi-directional force-sensing [ 71 ]. The sensor was based on a dielectric layer of a carbon black/PDMS composite and upper and lower electrodes of carbon nanotubes (CNTs)/PDMS composite layer.…”

“…This was explained according to the percolation theory. The prototype with the carbon black/PDMS composite dielectric layer was fabricated and characterized, and it was concluded that the resolution of the carbon sensor could reach 0.1 N within 50 N in a normal direction, and 0.2 N in 0–10 N in a tangential direction, with good stability [ 71 ].…”

“…Different fillers can be synthesized in various shapes and mixed to improve the charge transfer path. In [ 71 ], researchers used several composites of fillers: three types of carbon nanomaterials were used as conductive fillers, including zero-dimensional (0D) carbon black, 1D CNTs, and 2D graphene. The combination of different conductive fillers was beneficial because it was possible to effectively lower the percolation threshold of composite conductive fillers.…”