Design of Photovoltaic Cells to Power Control Electronics Embedded in Untethered Aqueous Microrobots Propelled by Bacteria

The preliminary design of photovoltaic cells to be embedded in untethered aqueous microrobots, a few hundred micrometers in overall length, is briefly described. A total of 4 cells with an estimated efficiency of 12.5% should provide up to 100 microamperes of photonic current to the electronics embedded in each untethered microrobot from an incident source of green light. The need for power has been minimized through the use of magnetotactic bacteria (MTB) acting as embedded micro-actuators to propel the microrobots in an aqueous medium. Controlling the direction of propulsion with the onboard electronics would be performed by exploiting magnetotaxis inherent in MTB. Here, a small electrical current provided by the photovoltaic cells and flowing in a controlled manner in a special embedded conductor network would be sufficient to exert a torque on a chain of magnetosomes in each bacterium. Such approach allows us to independently change their direction of motion when pushing each microrobot