Earthworm inspired locomotive motion from fast swelling hybrid hydrogels

摘要

Abstract Diverse motion mechanisms encountered in nature serve successfully as a guide for engineering efficient mobile devices used in cargo transport and force generation. We have previously demonstrated earthworm locomotion inspired directed motion and cargo transport using a pNIPA hydrogel‐based device. The motility mechanism involved sequential shrinking and swelling of segments of a long gel in a glass capillary, induced by volume phase transitions, through a simple temperature stimulus using peltier elements. The same effect is generated in the earthworm by flexing and stretching muscles along the body as it moves in its underground burrow. The shrinking segments move the body forward while the swollen segments anchor against the walls to prevent slippage. Here, we show an improved device, using the same working principle, made of super‐porous, mechanically robust organic‐inorganic hybrid hydrogels (also known as nanocomposite hydrogels), which show large volume phase transitions above 32 °C without requiring lengthy hydrolysis times. The gels demonstrate fast swelling kinetics with complete restoration of their initial size in short times, making the gels reusable for multiple cycles. This improved device, with its reusability, fast swelling kinetics, and efficient slip‐free motion, opens a variety of possibilities for applications in microfluidics, nanobiotechnology, small‐scale robotics, and micro electro mechanical systems. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5027–5033, 2009