Ultra-Sensitive, Deformable and Transparent Triboelectric Tactile Sensor based on Micro-Pyramid Patterned Ionic Hydrogel for Interactive Human-Machine Interfaces

Rapid advances in wearable electronics and mechno-sensational human-machine interfaces impose great challenges in developing flexible and deformable tactile sensors with high efficiency, ultra-sensitivity, environment-tolerance and self-sustainability. Herein, we report a tactile hydrogel sensor (THS) based on micro-pyramid-patterned double-network (DN) ionic organohydrogels to detect subtle pressure changes by measuring the variations of triboelectric output signal without an external power supply. By the first time of pyramidal-patterned hydrogel fabrication method and laminated PDMS encapsulation process, the self-powered THS shows the advantages of remarkable flexibility, good transparency (~85%), and excellent sensing performance, including extraordinary sensitivity (45.97 mV Pa-1 ), fast response (~20 ms), very low limit of detection (50 Pa) as well as high stability (36000 cycles). Moreover, with the LiBr immersion treatment method, the THS possesses excellent long-term hyper antifreezing and anti-dehydrating properties, broad environment tolerance (-20 to 60 ℃), and instantaneous peak power density of 20 μW cm-2 , providing reliable contact outputs with different materials and detecting very slight human motions. The THS shows no apparent output decline under the extreme environments of −29℃, 60℃ and even the vacuum conditions, demonstrating the excellent application potential in the field of harsh environments. By integrating the signal acquisition/process circuit, the THS with excellent self-power sensing ability is utilized as a switching button to control electric appliances and robotic hands by simulating human finger gestures, offering its great potentials for wearable and multi-functional electronic applications.