Nextreme Thermal Solutions (Durham, NC) and Infinite Power Solutions, Inc. (Denver, CO) offer a thermal charger that can continuously recharge the IPS THINERGYTM Micro-Energy Cell (MEC) using an eTEG thermoelectric power generator from Nextreme. Storing energy harvested from waste heat using thermoelectrics enables an alternative energy source for various autonomous applications.

The prototype thermal charger uses an array of 16 HV14 modules in power generation mode to provide the 4.1 volts of electricity needed to charge the MEC to a fully charged state. This takes approximately 20 minutes. A 0.5 millimeters high, four of the HV14 power generators can replace a AA battery.

With modules measuring just 1.8mm x 1.5mm, the eTEG HV14 has corresponding output power densities of ~ 0.6 and 1.6W/cm². Nextreme's eTEG devices generate electricity via the Seebeck Effect - where an electrical current is produced from a temperature gradient across the device.

Unlike conventional batteries, the ultra-thin and rechargeable THINERGY MECs can be solder attached directly to printed circuit boards (PCBs), or deeply embedded within the layers of a PCB. The MECs can also be embedded into integrated circuit (IC) packaging and multi-chip modules, as well as systems in package. The THINERGY MEC is provided to supply stored energy for use by the application during periods when the heat source is not available or is intermittent.