Researchers have created a unique robotic finger that is capable of using perspiration to cool down thanks to its 3D printed hydrogel actuators, In a similar way to how the human body sweats when its heat rises.
“Here, we demonstrate a hydraulically actuated soft machine, a hand, that thermoregulates via autonomic, localized sweating through microscale pores. Unlike previously reported hydraulically actuated soft manipulators (13), our hand incorporates dynamic pores that change dimension with temperature and high surface area texture that enhances evaporative cooling.
We fabricated the fingers of this hand using a custom-built multimaterial stereolithography (SLA) three-dimensional (3D) printing (14–16) approach to selectively photopolymerize finger-like actuators composed of two hydrogel materials with distinct responses to temperature—a poly-N-isopropyl acrylamide (PNIPAm) actuator body that is capped with a porous polyacrylamide (PAAm) layer.
At low temperatures (T ≤ 30°C), the fingers of the hand perform like a typical fluidic elastomer actuator. At higher temperatures (T > 30°C), the PAAm layer expands, causing the pores to increase their diameter, resulting in the pressurizing fluid “sweating” out of the actuator. Our autonomically perspiring system cools the actuator via evaporation, yielding an ΔT ~ 21°C reduction in the surface temperature of these functionally graded actuators within 30 s when the actuating fluid temperature is Thyd ~ 70°C.”