Environmentally Stable and Self-Recovery Flexible Composite Mechanical Sensor Based on Mechanoluminescence

Mechanoluminescent materials featuring mechanical-to-optical conversion have been vigorously studied as a carrier of optical sensing technology in the field of mechanical sensing due to their self-recovery, visualization, and non-contact sensing characteristics. However, the impact of the human living environment such as temperature, humidity, corrosive substances, etc. on optical sensing materials cannot be ignored, which greatly affects the accuracy of optical sensing. To overcome these barriers to the accuracy of these factors, a flexible mechanoluminescent composite device with high brightness in a bright and dark environment based on Ce3+-doped garnet structure phosphors Tb3Al5O12 was proposed. Under the action of repeated mechanical stimulation, the mechanoluminescence (ML) intensity presents good self-recovery performance, and the ML intensity shows a zero-thermal-quenching performance in the range of 0–100 °C. In addition, the evaluation of moisture resistance was performed under different durations in the water, proving that the intensity of ML can hardly be affected by the humid environment. Accordingly, a transmission system based on a robot finger was proposed to simulate the application of the human tactile system. The results showed great potential for Tb3Al5O12: Ce3+-based ML composite devices in advanced optical multimode sensors to promote their diversified application.