A self-swimming microbial robot using microfabricated nanofibrous hydrogel

Micro-robots are of extreme interest for a wide range of applications. Examples include therapeutic applications inside of a living body and automatic untethered systems which work in microfluidic devices. Recently, flagellated bacteria have been employed as microactuators for the micro-robots. Here, we introduce bacterial cellulose (BC) as an effective support carrier for immobilizing flagellated bacteria. Experimental study revealed that the superiority of BC over conventional MEMS materials in immobilization. Next, a new microfabrication technique for forming conical-shaped BC is proposed. This technique achieved the untethered microstructure of BC with a help of oxygen concentration gradient. Finally, we demonstrate motile bacteria were successfully immobilized onto the BC structure to form a microbial-robot, which swam in culture media at an average speed of 4.8 mu m/s. (C) 2014 Elsevier B.V. All rights reserved.