A team of scientists from the University of Washington presented a technology for remote charging of gadgets using a laser. During the experiment, they installed a battery in the back of the smartphone and directed a narrow laser beam in the near infrared part of the spectrum from a distance of 4.3 m at it, which generated 2 W of power over an area of 100 sq. Cm. As a result, the mobile phone was charged as quickly as with a regular USB cable.
The laser emitter automatically determines the readiness of the gadget for charging, so that people do not accidentally get hurt, being in the irradiation zone, four low-power beams are generated around the main laser, which are reflected and directed back to the emitter. If at any moment the signal is interrupted, the system is instantly turned off.
To dissipate excess heat generated by the charging beam, the researchers used strips of aluminum as a heat sink around the emitter. At the same time, not all heat is lost without a trace. Some of the energy is collected by a thermoelectric generator and returned to the phone battery.
According to scientists, such charging systems in the future will be able to charge mobile devices from a distance of 12 meters on an area of 100 square meters. centimeters.