Compact proof-of-concept platform for prototyping ambient micro-energy harvesting

Called Severn, the compact platform can be used as a prototype because its size and form factor could be adopted for production.

An engineering sample of the TM2040, a four-input, smart EH PMIC is at the heart of Severn. Up to four harvesters of the same or mixed type can be connected to any of its inputs without additional interface components. Each harvester typically generates microwatts to milliwatts of power.

The Severn platform includes a photovoltaic (PV) harvester on a hinged backing to allow optimal positioning and a thermoelectric generator (TEG) with an air heatsink, all housed in an acrylic case. Magnets facilitate the platform's attachment to a warm, ferrous surface when working with the TEG. Daughter boards are supplied to allow for additional harvester inputs, deliver output power to the application, and communications. A Windows GUI is also available, which can display harvested power and status information.

The user locates the Severn where there is an artificial or natural light source for the PV panel and a warm surface relative to ambient air for stimulating the TEG.

The TM2040’s inputs adapt autonomously to the harvester type connected, and any changing ambient conditions, maximising energy capture. The PMIC then combines the energy from each input into a common store. On the Severn platform, this store is a super-capacitor. When the capacitor is fully charged, the TM2040 delivers a 1.8V DC, regulated supply at up to 15mA for powering wireless IoT sensors and modules.

Micro-energy harvesting is a key enabler in the development of autonomous sensors that do not require batteries, or for sensor applications where there is a need to minimise the number of battery changes over the sensors’ operating life.

Huw Davies, CEO of Trameto, said: “The Severn platform is an example of how to create a reliable power supply for an edge IoT device from ambient light and/or heat in a compact form-factor, and showcases the TM2040's ability to manage the energy simultaneously and effectively from multiple harvesters.”

The Severn platform is available now and a user guide can be downloaded from https://trameto.com/resources/.