The development of an autonomous self-powered bio-sensing actuator

The inherent low power supplies from biofuel cells limits their application as power sources in implantable devices. To overcome these limitations, we have previously developed a novel device designated as a "BioCapacitor" (Hanashi et al., 2009). The BioCapacitor generates sufficient stable power to operate biosensing devices and signal transducers. In this paper, we report an autonomous, self-powered, sensing actuator that employs the principle of BioCapacitor as the core technology. The device is composed of a BioCapacitor, which uses a direct electron transfer-type glucose enzyme fuel cell, connected to a stepper motor as the actuator. In the presence of glucose, the BioCapacitor was able to generate enough electricity to operate the actuator. The torque and rotational speed of the stepper motor was dependent on the capacitance of the capacitor used in the BioCapacitor, and on the glucose concentration. A higher glucose concentration provided the stepper motor with higher torque and speed, resulting from the charge/discharge frequency of the capacitor as a function of the enzyme reaction at the anode. The actuator was operated entirely by the energy derived from glucose oxidation, and its performance was regulated by the glucose concentration. We also present the performance of a liquid-pumping system that employs the autonomous, self-powered, sensing actuator, which demonstrates its potential for application as a drug delivery/pumping system. (C) 2014 Elsevier B.V. All rights reserved.