Research and development into MEMS (micro-electromechanical systems) that harvest and generate their own energy will have applications in a variety of areas that require small sensors and accelerometers, according to a new report from Yole Development.
Energy harvesting has the most viability, says Yole analyst Laurent Robin, in conjunction with other technologies, such as wireless sensor networks. "In that situation, you need wireless technology that consumes little power. A distance of ten meters can be enough, and you don't need to transmit high amounts of data. You can do it with RFID, Zigbee or Bluetooth."
Robin cites viability in a variety of industries, noting that products are already available in some building and home automation and military and aerospace applications, and very soon in the automotive field. He cites the example of the PTM 200 wireless switch from EnOcean, a spinoff of Siemens, which could be set up as any kind of switch, including use with lights. "When the user pushes the clip, it generates energy that sends a signal to a receiver to put the light on. You save money by not having to wire another switch, and you have the flexibility to put it anywhere."
In military and aerospace applications, vibrations can be harvested to power a sensor running what's known as a health and usage monitoring system (HUMS) for either helicopters or fixed-wing aircraft. These systems, made by companies such as RSL Electronics, can be programmed with accelerometers to measure the state of components or sensors to gauge temperature.
He believes that other industries, such as medical, consumer electronics, and environmental applications, still need more R&D work. According to Robin, there are four technologies for creating these MEMS: electromagnetic or electrostatic systems; piezoelectric films; or thermal systems. Each has its challenges in terms of manufacturing efficiency. Even so, he cites some 21 companies tackling this area of energy-harvesting MEMS, which indicates a lot of R&D dollars pursuing an eventual solution.