(17f) Induction Heating of Microwheels for Melting and Clearance of Gelatin-Based Blockages

Microscale bots (microbots) have significant interest for their ability to perform targeted drug delivery where systemic methods are limited due to harmful side effects. Another potential application for microbots is hyperthermia to aid in cancer treatment or mucus clearance for lung conditions like cystic fibrosis. We have previously shown that superparamagnetic 4.5 µm colloidal beads can reversibly assemble into microwheels (µwheels) under a rotating magnetic field and translate rapidly. Here, we demonstrate that µwheel components can be heated with induction heating. Using a weak induction coil frequency of ~67 kHz and a bead concentration of ~2 × 10⁸ beads per ml, calorimetry experiments were able to achieve a max temperature increase of ~9 ËšC for 1 ml of water. We then demonstrate how heated µwheel components can be used to melt gelatin-based blockages. Gelatin solutions derived from tilapia fish skin were used with 1 mm square capillary tubes to create our blockage system. For 5% fish gelatin solution, the melting temperature was measured to be ~25 ËšC which is about 5 ËšC higher than the room temperature where experiments were conducted. We show that µwheels were able to transfer heat to blockages for melting and clearance.