Thermoelectric (TE) energy harvesting is based on the heat flux through a thermoelectric element or a thermogenerator comprising a multitude of such elements. The heat flux is driven by a temperature difference across the element. The generated voltage is proportional to the number of elements and the temperature difference. Thermoelectric thin-film micro devices with high packing densities of thermoelectric legs are of high demand in micro-systems for waste-energy harvesting self-powered battery-less wireless sensor systems for wireless data transfer. One technical solution for such micro-devices is offered by the Micropelt technology. Micropelt GmbH develops, produces, and markets the world’s smallest and most effective thermoelectric elements for clean-tech micro energy harvesting, thermal sensing, cycling, and cooling.

Micro Thermogenerators Challenge Batteries

Waste Heat Energy Harvesting Micro Thermogenerators for Self-Powered Wireless Sensor SystemsMicropelt’s new Thermogenerator Package (TGP) makes thermal energy harvesting ready for mass production. The new device allows for automatic assembly of autonomous DC power supplies for ultra-low-power wireless sensors and actuators. Battery maintenance, so far preventing wireless monitoring sensor networks from really taking off, can be eliminated by TGP-enabled autonomous DC power modules whenever a temperature difference of 5°C or more is available. Output power ranges from 100 µW to over 10 mW, sufficient to offset most batteries.

Micropelt thermogenerators contain hundreds of such elements, also referred to as leg pairs – 10 to 100 times more than conventional TE devices. Hence their thermogenerators produce voltages in the range of 0.5 – 5 Volt depending on actual temperature differences on some 12 square millimeters of footprint – sufficient energy to drive a wide range of low-power wireless applications including remote sensors, data loggers and small actuators.

Micropelt’s thermoelectric chips are based on a patented, scalable thin-film micro-structuring platform technology, which minimizes component size while maximizing power density for energy harvesting, cooling, or thermal-cycling applications. Process-inherent economies-of-scale break previous cost and price barriers of conventional thermoelectrics. Batteries become obsolete as cost-free electricity from waste heat powers wireless sensors and actuators for their entire life. Chip-thermogenerators also boast unprecedented sensitivity, resolution, and dynamics in sensing heat flux and temperature change.