Wirelessly transmitting power over 98 feet of air


Wirelessly transmitting power over 98 feet of air, Newly discovered technology may one day allow us to charge our mobile devices wirelessly through the air.

Researchers have managed to send 400mW of light output from an infrared laser over a distance of 30 meters (98 feet). Powerful enough to juice up miniature sensors, this technology has the potential to grow to support charging for larger devices like smartphones in the future.

This is accomplished in a completely safe manner, as the laser automatically switches to a low-power mode when it is not in use.

Technically referred to as “distributed laser charging,” this method is both safer and more effective than similar attempts at wireless power transmission in the past.

Electrical engineer Jinyong Ha from Sejong University in South Korea notes that while most methods require the receiving device to be in a special charging cradle or to be stationary, distributed laser charging enables self-alignment without tracking processes as long as the transmitter and receiver are in the line of sight with each other.

Typically, a laser cavity’s many light-reflecting parts would all reside within the same physical apparatus. In this case, the transmitter and receiver are physically separated, with the result that the laser cavity forms between them whenever the two are in the line of sight.

Thirty meters separated the amplifier transmitter, which was coated with a silvery-white metal called erbium, from the receiver, which was equipped with a photovoltaic cell to transform the light signal into electrical power.

This receiver can fit into small devices like sensors thanks to its tiny size of about 10 millimeters by 10 millimeters (0.4 inches by 0.4 inches). This might be used to wirelessly charge smaller smart home devices, such as motion or temperature sensors.

The day is coming when you can use your phone at an airport and have it charge at the same time, without needing any sort of cord or socket. However, this cannot occur until the team has increased the amount of energy that can be transferred by the system.

The receiver’s solar cell could be improved as part of this procedure in order to increase the amount of energy gained from the laser’s radiation. Adding support for several receivers at once is another area for development.

The laser’s primary wavelength of 1550 nanometers places it in the infrared’s safest section of the spectrum and protects against the skin and eye damage. To ensure the maximum amount of energy was transferred, the scientists made a number of additional adjustments to the device.

According to Ha, “we added a spherical ball lens retroreflector in the receiver unit to permit 360-degree transmitter-receiver alignment, which maximized the power transfer efficiency.

We found that the 2.003 refractive indexes of the ball lens provided the best overall system performance in our experiments.

Although it is still in its infancy, wireless energy transfer has the potential to make a major difference in industrial settings where cabling is difficult to install and maintain, as well as in consumer gadgets.

Ha believes that maintenance and repair expenses could be reduced by using laser charging technology in place of power wires in industries.

In “harsh situations where electrical connections can produce interference or constitute a fire hazard,” this could be very helpful.