Powercast RF Energy Harvesting powers Crossbow IRIS Mote
In the later part of 2008, Powercast began to demonstrate RF energy harvesting technology working with wireless sensors. An initial project was to wirelessly power a sensor platform from Crossbow Technology. Crossbow is a leader in the wireless sensor market and has a range of wireless sensor platforms, including the agricultural-specific eKo system.
Powercast integrated wireless power technology based on RF energy harvesting with Crossbow’s IRIS Mote platform (shown at right) and their MTS420 sensor board. The IRIS Mote was situated on top of a Powercast lab board as shown in the photo below and monitored with Crossbow’s MoteView user interface.
We could have just recharged the batteries with wireless power, but it’s hard to visualize that. So, we substituted a supercap for the batteries and connected that to the IRIS board. The power source was a 900 MHz transmitter (Powercaster™) designed by Powercast.
The IRIS Motes were loaded with the LP code which supports mesh networking and were programmed to wake up 8 times per second. Powercast will be continuing this effort with Crossbow’s ELP code (lower power, no mesh support) and have the motes sleep for a much longer period. This lower power configuration will provide for battery-free operation at a greater distance.
Crossbow has a related post on their blog about our visit to their office to make this demonstration.
Low power, low data rate wireless sensors such as Crossbow’s IRIS mote are great candidates for being powered by RF energy harvesting.
While this was just a concept of what can be done with RF energy harvesting, it’s an exciting proof point of the potential of wireless power.
Powercast anticipates that energy harvesting will be key to the next stage of growth in the wireless sensor market, and forsee our RF energy harvesting technology as a way to further expand the market and applications with a predictable wireless power platform.
Energy Harvesting and Micro-Power