- Researchers have developed a silicon-based sensor as a microelectromechanical system (MEMS), small, grid-shaped silicon structures measuring just a few micrometres in size are fixed onto a small spring.
- This sensor has the major advantage that it does not distort the very electric field it is currently measuring.
- The equipment currently used to measure electric field strength has some significant downsides.
- 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.
- When the silicon is exposed to an electric field, a force is exerted on the silicon crystals, causing the spring to slightly compress or extend.
- These tiny movements now need to be made visible, for which an optical solution has been designed: an additional grid located above the movable silicon grid is lined up so precisely that the grid openings on one grid are concealed by the other.
- When an electric field is present, the movable structure moves slightly out of perfect alignment with the fixed grid, allowing light to pass through the openings.
- This light is measured, from which the strength of the electric field can be calculated by an appropriately calibrated device.
- The new silicon sensor does not measure the direction of the electric field, but its strength.
- It can be used for fields of a relatively low frequency of up to one kilohertz also measure weak fields of less than 200 volts per metre.
- This means this system is already performing at roughly the same level as existing products, even though it is significantly smaller and much simpler.
Accurately measuring electric fields is important in a variety of applications, such as weather forecasting, process control on industrial machinery, or ensuring the safety of people working on high-voltage power lines.