Do you use batteries in remote locations that can’t be accessed for replacement? Do you need to get power into locations where it can’t be delivered by electromagnetic means? Consider active wireless recharging via ultrasound, or passive recharging in situ through energy harvesting, using our two patented and patent-pending technologies.
The first application of our technologies has been to power medical devices implanted in the human body. Active Ultrasound Electrical Recharging (USerTM) uses ultrasound waves to transfer energy through tissue to a receiver and then to a rechargeable battery or capacitor. Power can also be provided to an application for direct use. This project was originally funded by Phase I and Phase II SBIR grants from the National Institutes of Health. Conversely, passive energy harvesting takes advantages of the natural forces within the human body such as joint and muscle movement or heartbeat, converted via piezoelectric materials to electrical energy, to develop small amounts of power for sensors.
With USerTM we have transmitted energy wirelessly through water, tissue, and various liquids, metals and plastics, over distances of 0.1 to 20 cm. Wireless power transmission of a Watt through 1 cm of a tissue in vivo has been demonstrated. The method can be applied to batteries for implanted medical devices such as drug pumps, sensors, and neurostimulators.
In piezoelectric energy harvesting, the material is subject to forces in the body that create an electric charge which can be transferred to a capacitor or rechargeable battery. Capacitor charging power of almost 2 mW has been demonstrated in the laboratory. The storage device can then power, for example, a medical device that has low power requirements such as a pacemaker, or an implanted sensor.