Photovoltaic cell arrays are used on robotic rovers on the Mars surface, but dust accumulation on the surface of the solar cells reduces their exposure to light radiation and thus degrades their performance. Dust that accumulates without being removed limits the life of the rover’s power systems. Similarly, terrestrial solar arrays suffer from dust accumulation, especially when located in desert areas, which reduces their effectiveness. Technologies for re moval of the dust or preventing it from settling have been proposed and are being researched, but none were yet implemented on the rovers. These techniques include mechanical means, blowing stored gas, blowing pumped gas, electrically charging the surface, repelling the dust, and other techniques.
The innovation is the use of a device to remove dust from solar cells operating on Mars, on Earth, or in any atmosphere. The device is a barrier discharge plasma (BDP) actuator driven by AC voltage. It creates a velocity stream from the atmospheric surrounding gas that blows dust off the solar cell surface. The device has low power consumption, is integrated with the solar cells, and is suitable to operate with solar cells that power Mars rovers or generate electric power on Earth and suffer from performance degradation due to dust accumulation.
The dust is removed by blowing a stream of gas generated by an electronically operated device. The device is based on an actuator that imparts momentum or velocity to the surrounding atmospheric gas in a direction parallel to the surface. It consists of two electrodes separated by a dielectric. The electrodes are arranged in a specific configuration; the simplest configuration is two offset strips, but more complex configurations are possible. The present concept uses one exposed electrode on the surface and one electrode buried under the dielectric, but both electrodes can be buried. AC voltage, typically in the RF (radio frequency) range of 1 to 20 kHz, in Mars applications to several thousands of volts in Earth applications. The electric current is very low, in the range of tens of milliamperes. The voltage can be pulsed or modulated to increase effectiveness and reduce power consumption. The applied voltage creates barrier discharge plasma — plasma that is localized on the surface near the surface electrode. The plasma creates a body force in the surrounding gas that induces a velocity in the gas tangential to the surface.
This innovation has several novel features. It is a simple, lightweight, purely electronic device without moving parts, and there is no need to carry a supply of gas in a tank. The blowing stream is created from the surrounding atmosphere. It is powered from the available power system using a simple converter circuit.