Liquid crystal to replace space motors?

1 min read

Researchers claim to have devised a way to eliminate the need for motors in space borne radiometers by incorporating liquid crystals in frequency selective surface (fss) antenna arrays.

The discovery has been made by teams from the Institute of Electronics, Communications and Information Technology (ECIT) and the Northern Ireland Semiconductor Research Centre (NISRC) at Queen's University Belfast. The ECIT project is addressing frequencies ranging from millimetre wave up to 1THz; measuring radiation in this waveband is a key technique used to study the earth's atmosphere. Current remote sensing radiometers that collect such data incorporate a turntable mounted mirror operated by an electric motor to calibrate the instrument before each scan by directing the field of view between cold and ambient targets. The teams have devised a technique for making such motors redundant by sandwiching layers of liquid crystals between the fss' metalised quartz layers to act as an electronically controlled shutter. Applying a small voltage to the structure then enables the radiometer to be switched from calibration mode to signal detection mode without mechanical components. According to the researchers, the technique to replace the motor and turntable could produce potential weight savings of 10% per radiometer and could greatly reduce power consumption requirements as a motor represents a radiometer's single biggest power requirement. The researchers claim that the technology also has the potential to be used to eradicate the attenuation of mobile phone signals passing through energy efficient glass. In theory, it could also help create buildings that can be locked down to block radio signals at the flick of a switch. Prototypes are currently being built at Queen's University's Northern Ireland Semiconductor Research Centre and the devices are expected to be used in space missions from 2025 onwards. The project has already received funding of £0.5million from the European Space Agency and £100,000 from economic development agency, Invest Northern Ireland.