Sub-millilitre Microbial Fuel Cell Power for Soft Robots

Conventional rigid-body robots operate using actuators which differ markedly from the compliant, muscular bodies of biological organisms that generate their energy through organic metabolism. We consider an ‘artificial stomach’ comprised of a single microbial fuel cell (MFC), converting organic detritus to electricity, used to drive an electroactive artificial muscle. This bridges the crucial gap between a bio-inspired energy source and a bio-inspired actuator. We demonstrate how a sub-mL MFC can charge two 1F capacitors, which are then controllably discharged into an ionic polymer metal composite (IPMC) artificial muscle, producing highly energetic oscillation over multiple actuation cycles. This combined bio-inspired power and actuation system demonstrates the potential to develop a soft, mobile, energetically autonomous robotic organism. In contrast to prior research, here we show energy autonomy without expensive voltage amplification.