One of the biggest issues facing electric cars is range. While EVs might be ideal for inner city commuting or short distances, anything over 200 miles and even an advanced car like the forthcoming Tesla Model 3 is going to need a recharge. This of course takes time, so it makes long distances a challenge for electric vehicles to overcome. Now scientists from Stanford University have made a significant step towards getting round this problem – by successfully transferring electricity wirelessly to a moving object.
The ability to transfer electricity in this way has the potential to revolutionise the world of electric vehicles. If a car was able to be charged while it was being driven, then this would solve the problem of limited range and enable vehicles to travel for potentially unlimited distances. The idea is that a coil on the bottom of a car could receive electricity from coils that are connected to an electric current that is embedded in the road.
At the moment, the team at Stanford has been able to wirelessly transfer enough electricity to power a 1-milliwatt LED bulb. Obviously, an electric car will require a much greater amount of electricity, and increasing the amount of electricity is the next goal that the team is working towards.
Potential Applications for Robotics
The transfer of electricity in this way is based on magnetic resonance coupling, where electricity moving through wires creates an oscillating magnetic field which causes electrons in nearby coils of wire to oscillate. The result is a wireless transference of power. There are a number of challenges with this method, and normally for the continuous flow of electricity to be achieved, the receiving and transmitting coils need to be stationary, or they must be continuously tuned automatically. The Stanford team solved this problem by using a voltage amplifier and feedback resistor to replace a radio-frequency source in the transmitter. The result was that power was able to be transferred across a range of up to 3 feet, without the need for either the continuous tuning of the circuits, or remaining stationary.
This new development has further reaching potential than just electric vehicles. In time, we may be able to wirelessly charge all of our devices, and there are numerous opportunities for use in robotics. The future is untethered.