Electric Power at the Touch of a Finger | Germany| News and in-depth reporting from Berlin and beyond | DW | 12.06.2002
  1. Inhalt
  2. Navigation
  3. Weitere Inhalte
  4. Metanavigation
  5. Suche
  6. Choose from 30 Languages


Electric Power at the Touch of a Finger

When Thomas Edison invented the light bulb, he lit up the world. Now there’s a new German concept in illumination – one that doesn’t require batteries or wires, but rather converts fingertip energy into electricity.


Electricity has come a long way since the invention of the light bulb

Remember the "Clapper" of the 1980s? Clap on, clap off – a light switch that worked like magic at the clap of the hands? Well now there’s a clever new electronic device waiting to revolutionize the way we turn lights on and off. And it’s very much in keeping with the 21st-century notion of energy-efficient technology.

Developed by the German company EnOcean in conjunction with Siemens Corporate Technology department, the wireless, battery-less light switch requires no external power supply. It requires no extensive electrical wiring and virtually no installation.

It is a self-sufficient system that "supplies itself" by collecting available, unused environmental energy that exists everywhere in small amounts. Special sensors are built onto the switch to sense or absorb surrounding energy and convert it into electricity for sending a radio signal to a lamp. Thus, the simple touch of a finger on a light switch, in a sense, generates enough energy to turn on a light.

How it works

The new EnOcean light switch is based on the physics of energy transformation and radio transmissions.

According to the basic laws of physics, all detectable events taking place around us cause changes in the energy entropy, the amount of energy available in the environment. When we press a light switch, for example, our movement and finger pressure set off mechanical energy. Normally, this energy remains unused, and the light switch draws from an outside source, either electricity supplied by a current running through a wire or a battery. But in the case of the EnOcean light switch, special energy sensors capture the mechanical energy and convert it into electricity by way of tiny piezoelectric crystals.

EnOcean Funkmodul

EnOcean radio transmitter installed in light switch

The concept is actually not so unusual. In fact, a similar process of energy transformation via piezoelectric crystals takes place in an ordinary cigarette lighter. The mechanical pressure applied to the lighter’s push-button sets off a surface charge across the face of the crystals. When the charge is especially high it results in electric volts moving rapidly across the crystals. In a cigarette lighter this charge is so intense that it creates a spark. In the case of EnOcean technology, however, the voltage is kept considerably lower – just high enough to generate electricity for running the next stage of the process.

How does the electricity get from the light switch to the lamp? Since there are no wires to transport the electric current to the light bulb, the EnOcean device relies on radio transmissions.

The electricity generated in the light switch sensors is used to activate a built-in transmitter. This in turn sends a radio signal to a receiver in the corresponding light fixture. An identification code embedded in each radio transmission "tells" the light to turn on or off. Each code links up exactly one switch with one receiving fixture, and each signal can be received up to 300 meters away.

Lighting up the world

Next year, when the EnOcean radio light switch comes out on the market, it will allow for the operation of entire lighting systems in buildings. Initially the switches will be more expensive than conventional ones. But wiring a building from scratch with the new technology will cost about 80 percent less than traditional lighting, says Armin Anders, the company’s product marketing director. This is because the EnOcean technology eliminates complex installation work, wires, cables and batteries. Because the new technology makes use of previously unused energy, it also does not require an expensive external source – the energy is available in the surrounding environment.

The EnOcean switch and sensor technology is like a "mini power station" that can be adapted and integrated to fit into various systems, says Anders. In the near future, EnOcean envisions the production of several more devices that make use of its patented technology, such as temperature sensors which respond to a change in temperature, vibration sensors which respond to a change in seismographic activity and position sensors which respond to motion.

In 2004 the company plans on marketing a battery-less car entry key, and in 2005, it hopes to introduce self-powered sensors for monitoring tire pressure and temperature. Both of these products will rely on the company’s innovations in the fields of sensors and energy transmission.

Enocean Logo

EnOcean company logo

The power of unused energy

Since EnOcean’s establishment in 2001, the small company has been guided by the basic idea of developing innovative, cost-saving products which utilize formerly unused energy. The energy is out there, the company says, available for anyone to use and harness for conversion into a different form. Even the company’s name is derived from this principle of vast and unlimited energy.

In its company brochure, EnOcean writes, "A sea of energy surrounds us. That’s what our company name symbolizes – Energy Ocean."

WWW links