A flexible self-powered multimodal sensor with low-coupling temperature, pressure and humidity detecting for physiological monitoring and human-robot collaboration

Abstract

The multifunctional capabilities and low coupling of flexible sensors are of significant importance in sophisticated robotic systems that directly interact with the external ambient or the human body. Despite flexible sensors have advanced considerably in multifunctional sensing, it is still difficult to achieve self-powering and differentiate between various stimulus signals. Herein, a flexible self-powered temperature/pressure/humidity multimodal sensor with multichannel mode was developed by coupling thermoresistive, triboelectric, and humidity-sensitive effects. The multi-parameter sensor shows the capability of effectively converting temperature, pressure, and humidity stimuli into three separate electrical signals while exhibiting low signal interference, Furthermore, the temperature sensor is driven by the natural temperature gradient, with a high sensitivity of −0.055 °C⁻¹ below 40 °C. The self-powered pressure sensing process based on the triboelectric effect can measure the pressure within a broad range (0.2–120 kPa) and has a maximum sensitivity of 8.254 V kPa⁻¹. The device also displays reliability in detecting environmental humidity. It has been demonstrated that the sensor attached to the robotic hand can simultaneously detect environmental humidity, as well as the temperature and weight of a water cup. This work presents an innovative passive multimodal electronic skin architecture, having superior integrated sensing performance. Looking ahead, multifunctional electronic skin has enormous potential for applications in human/environment/machine interaction and wearable health monitoring systems.