TU Wien researchers have created a silicon-based sensor that acts as a microelectromechanical system (MEMS) to measure the intensity of electric fields. Compared to existing technology, the new device does not distort the electric field it is trying to measure, thus increasing accuracy.
These measurements are vital in a number of scenarios, including weather predictions, industrial process control, and ensuring the safety of workers in certain fields.
Considerable downsides plague current equipment, such as impracticality and not being transportation friendly.
“These devices contain parts that become electrically charged. Conductive metallic components can significantly alter the field being measured; an effect that becomes even more pronounced if the device also has to be grounded to provide a reference point for the measurement,” says Andreas Kainz from the Institute of Sensor and Actuator Systems.
However, the new sensor aims to streamline the process. For reference, below you can see the prototype compared to the size of a one-cent-coin.
At its design core, a small spring houses grid-shaped silicon structures that are only a couple micrometers in size. Once an electric field comes into play, a force is applied to the silicon crystals. These chain of events ultimately cause the tiny spring to extend or compress.
For the team to see the minute movements, they developed an optical solution. A second, fixed grid was precisely placed above the moveable silicon grid. When an electric field caused motion through the bottom structure, the two grids would fall out of alignment.
The misalignment creates openings, which allow light to pass. The resulting light is measured, and a calibrated device measures the strength of the electric field, but not its direction.
“Using our prototype, we have been able to reliably measure weak fields of less than 200 volts per meter,” says Kainz. “This means our system is already performing at roughly the same level as existing products, even though it is significantly smaller and much simpler.”
You can read the full research details in the article, “Distortion-free measurement of electric field strength with a MEMS sensor,” in the journal Nature Electronics.
