Abstract
<title>Abstract</title> <p>Adhesives capable of rapidly and reversibly switching between adhesive and non-adhesive states are desirable for a wide range of applications, including medical adhesives, robotic systems, bioelectronics, and scalable microassembly. In this study, we reported a poly(ionic liquid)-based ionogel that exhibited switchable adhesion to a variety of substrates in response to a mild thermal stimulus. This switchable adhesive behavior arose from the exposure of functional groups on ionogel surfaces caused by the temperature-induced collapse of polymer networks. The adhesion strengths of the ionogel were strongly temperature-dependent and exhibited a large tunable range, with an approximately 60-fold adhesion difference between low-temperature (1.4 kPa @ 0°C) and high-temperature (89 kPa @ 40°C) conditions. Using the ionogel as switchable adhesives on moving parts, three different robotic systems, including two climbing robots and a vertical transport tower, were implemented for application demonstrations. The tethered climbing robots are capable of climbing on various types of vertical walls, including ceramics, metal, wood, glass, plastic, and porous substrates. Locomotion on inverted walls was also demonstrated. In addition, stable vertical climbing with a payload that is 1.5 times greater than the robot’s weight was achieved. This study provides a facile and versatile strategy to endow ionogels with tunable, switchable, and dynamic adhesion performance that can expand the applicability of next-generation smart devices across various domains.</p>