Wireless Battery Charging Methods for Distributed Soldier Electronic Devices
Navy SBIR FY2008.2

Sol No.: Navy SBIR FY2008.2
Topic No.: N08-108
Topic Title: Wireless Battery Charging Methods for Distributed Soldier Electronic Devices
Proposal No.: N082-108-0078
Firm: Infoscitex Corporation
303 Bear Hill Road
Waltham, Massachusetts 02451-1016
Contact: James Goldie
Phone: (781) 890-1338
Web Site: www.infoscitex.com
Abstract: An inductive power transfer approach is proposed, in which a backpack-deployed central power source will deliver power omni-directionally to battery-powered devices also borne by the Warfighter. Charge will be maintained in batteries without removal from the devices they are powering and without the need for cables and connectors. Phase I will address the major technical challenges, including integration of the transmitter unit into the backpack and the receiver units into the battery holders of battery-powered devices; the tradeoff between device weight and transmission efficiency; and safety and detectability. Tasks during the Phase I base program will include (1) requirements definition for battery charging for a thermal weapon sight and/or other critical items, (2) design and construction of a power transmission prototype suitable for this application, (3) test of the prototype, in order to demonstrate its capability and to identify necessary design modifications, and (4) development of plots clearly presenting the major design tradeoffs. The Phase I Option will develop and document a full-scale design for a specific battery-powered item agreed to with Marine personnel, both with engineering drawings and illustrations and with a physical mockup.
Benefits: The characteristics of electromagnetic inductive coupling give it a number of advantages relative to other methods of wireless power transfer for distances up to 10 times greater than the characteristic dimensions of the transmitter. In particular, power transmission can go unimpeded from a transmitter to multiple receivers through most materials. In addition, although not truly omni-directional, good efficiency is achieved over a wide range of transmitter and receiver relative orientations. Inductively coupled systems that allow near omni-directional power transmission over distances of tens of meters, have limitless commercial and military applications, including, most particularly, those applications where motion hinders use of a wired connection, or where wiring is bulky or a nuisance. These include wireless power for cranes, elevators, robots, public transportation vehicles, electric cars and trucks, battery charging (for household appliances and laptops), remote sensors, surgical implants, and endoscopes. For the vehicle applications, transmitters would be embedded in or installed along public highways at periodic intervals. In general, wiring is cumbersome, bulky, and expensive to install and maintain in buildings and homes. The distances involved suggest that this is a prime application for inductive power transfer.