title: A flexible super-capacitive solid-state power supply for miniature implantable medical devices.
abstract: We present a high-energy local power supply based on a flexible and solid-state supercapacitor for miniature wireless implantable medical devices. Wireless radio-frequency (RF) powering recharges the supercapacitor through an antenna with an RF rectifier. A power management circuit for the super-capacitive system includes a boost converter to increase the breakdown voltage required for powering device circuits, and a parallel conventional capacitor as an intermediate power source to deliver current spikes during high current transients (e.g., wireless data transmission). The supercapacitor has an extremely high area capacitance of ~1.3 mF/mm(2), and is in the novel form of a 100 μm-thick thin film with the merit of mechanical flexibility and a tailorable size down to 1 mm(2) to meet various clinical dimension requirements. We experimentally demonstrate that after fully recharging the capacitor with an external RF powering source, the supercapacitor-based local power supply runs a full system for electromyogram (EMG) recording that consumes ~670 μW with wireless-data-transmission functionality for a period of ~1 s in the absence of additional RF powering. Since the quality of wireless powering for implantable devices is sensitive to the position of those devices within the RF electromagnetic field, this high-energy local power supply plays a crucial role in providing continuous and reliable power for medical device operations.
authors.affiliation: Center for Implantable Devices, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA, cmeng@purdue.edu.
authors.forename: Chuizhou
authors.initials: C
authors.lastname: Meng
authors.forename: Oren Z
authors.initials: OZ
authors.lastname: Gall
authors.forename: Pedro P
authors.initials: PP
authors.lastname: Irazoqui
mesh_terms: D025802:Electric Capacitance; D011211:Electric Power Supplies; D004864:Equipment and Supplies; D008904:Miniaturization / Q000295:instrumentation*; D019736:Prostheses and Implants; D011846:Radio Waves; D059015:Wireless Technology