Mar 1, 2018 | By Benedict

Engineers at the University of Washington have used 3D printing to create a wireless smartphone charging system. The system uses a narrow, invisible laser beam, and can potentially charge a smartphone as quickly as a standard USB cable.

The concept of wireless charging is a tricky one to get your head around, but it looks as though charging cables could someday be as obsolete as ethernet cables. Helping the cause for wireless charging is the University of Washington, where a group of researchers has devised a laser-based system for juicing up a smartphone.

The charging setup uses a narrow, invisible beam from a laser emitter that can charge a smartphone from across a room, potentially just as quickly as a standard USB cable can. It’s made possible by a thin power cell attached to the back of a smartphone, which absorbs that laser power to charge the device.

The charging beam is generated by a laser emitter configured to produce a focused beam in the near-infrared spectrum, with 3D printed “retroreflectors” placed around the smartphone power cell to reflect guard beams back to photodiodes on the laser emitter. These guard beams serve as a kind of sensor: if the guard beam is interrupted—by a human body, for example—the stronger, potentially harmful charging beam is paused.

This ultimately produces a laser system that is entirely safe to use. Although the charging beam is strong, these 3D printing-enabled guard beams make sure the laser only ever penetrates the phone’s charging cell.

“In addition to the safety mechanism that quickly terminates the charging beam, our platform includes a heatsink to dissipate excess heat generated by the charging beam,” says  Arka Majumdar, a UW assistant professor of physics and electrical engineering and researcher in the UW Molecular Engineering & Sciences Institute. “These features give our wireless charging system the robust safety standards needed to apply it to a variety of commercial and home settings.”

Researchers (c/w from top left) Vikram Iyer, Shyam Gollakota, Elyas Bayati, Arka Majumdar, and Rajalakshmi Nandakumar

(Images: Mark Stone / University of Washington)

In terms of power, a narrow beam can deliver a steady 2W of power to 15 square-inch area from a distance of up to 4.3 meters or 14 feet.

The charging system is, however, flexible and adaptable. For example, it can be modified to expand the charging beam’s radius to an area of up to 100 square centimeters from a distance of 12 meters, or nearly 40 feet, allowing the smartphone to be placed anywhere on a large surface, such as a tabletop.

A research paper about the wireless charging system, “Charging a Smartphone Across a Room Using Lasers,” has been published in Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies.



Posted in 3D Printing Application



Maybe you also like:


Leave a comment:

Your Name:


Subscribe us to Feeds twitter facebook   

About provides the latest news about 3D printing technology and 3D printers. We are now seven years old and have around 1.5 million unique visitors per month.

News Archive