Scientists Say Cell Phone in Your Pocket Could Charge Smartwatch On Wrist Wirelessly

Researchers in Singapore say they have found a way to charge gadgets worn by a person by tapping the human body as a medium for wireless power transmission. They say their technique draws power from one source, say a mobile phone kept in the person's pocket and transfers it to other gadgets worn by the person. The team from the National University of Singapore's (NUS) Department of Electrical and Computer Engineering said they developed this technique to address the body-shadowing issues encountered by wireless charging systems in a small indoor area.

In the system developed by the NUS team, each receiver and transmitter on the human body contains a chip that is used as a springboard to extend coverage over the entire body. A user needs to place the transmitter on a single power source, such as a smartwatch on their wrist and the system harnesses energy from the source to charge multiple wearables via a process called body-coupled power transmission. The user will only need to charge one device, which will then power the rest of the gadgets worn by them from that single source simultaneously.

Body shadowing, caused by the obstructive presence of the human body, can result in increased path loss in indoor wireless systems. Methods available today were unable to deliver sustainable power to charge wearables on the human body, the researchers said in a study published in the journal Nature Electronics, adding that instead of trying to send charge around the obstacle (human body), they used it as a conduit to harvest and transmit power.

The researchers also looked into ways to harvest energy from the environment. People are exposed to electromagnetic waves most of the time in a typical office or home environment, for example from a running laptop or other such devices. The team's method allows the body to harvest this energy to power wearable devices, irrespective of their location on the human body.

This could mean that you charge a watch simply by wearing it someday, instead of having to power up all the small gadgets you're toting around individually.