Electromagnetic triggering with metallic microparticles for prospective biomedical applications

Abstract

Biomedical devices like microfluidic chips and externally triggered drug delivery devices can activate their drug release mechanisms using external triggers such as ultrasound, electric field, alternating magnetic field and electromagnetic radiation. This work proposes an electromagnetic triggering technique based on the interaction of electromagnetic waves with metallic microparticles that are placed under a temperatures sensitive hydrogel. The heating effect of the electromagnetic interaction results in a localized rise in temperature. The change in temperature manipulates the physical structure of the hydrogel which can be used for releasing drug particles in a drug delivery device or controlling fluid flow in a microfluidic chip. The design and operation of the device is explained with the help of Multiphysics simulations in COMSOL followed by experimental verification using sub-100-μm iron powder particles placed under 2 mm thick layer of a thermosensitive hydrogel. The primary experiments for the device operating at 2.4 GHz and 145 mW show a temperature increment of 2.7 °C after 50 min.