Apple investigating solar-powered wireless mice and trackpads

An Apple patent application published by the U.S. Patent and Trademark Office on Thursday reveals continued research into alternative energy solutions, specifically as it applies to a lineup of wireless computer peripherals with embedded solar cells.

Like previous Apple inventions dealing with solar charging technology, "Wireless devices with touch sensors and solar cells" describes a device into which solar cells are disposed below transparent touch sensitive surfaces. However, instead of applying the technology to power-hungry portables like iPhone, Apple proposes integration with Bluetooth wireless keyboards, mice, multitouch track pads and other accessories.

In practice, light-based power sources are simply built into the functional top layers of a device. For example, solar cells could be embedded beneath capacitive sensor layers in Apple's Magic Mouse or Magic Trackpad, separated and stabilized by layers of liquid adhesive. During operation, the solar system gathers and converts ambient light into usable electrical energy, which is subsequently stored in a battery system or regulated capacitor. The device would then tap into harvested energy reserves to operate capacitive touch sensors, onboard processors, wireless radios and other components, potentially negating the need for batteries.

Some embodiments call for the solar cell layer to sit beneath both touch sensor and transparent protective cover layers, while others have energy producing elements sandwiched between the touch layer and protective cover. Apple notes orientation depends on material choice, as certain capacitive touch sensor designs inhibit light transmission.

In some iterations, ink or another material might be deposited above the solar cell components to obscure it from the view of a user. These substances would be opaque to visible light, but transparent in non-visible spectrums, perhaps infrared or fluorescent. While narrow, the material's transmission window allows for ambient light to pass through and hit embedded solar cells, allowing for energy conversion and storage. Apple notes visible-light-opaque layers can form brand logos or other aesthetically pleasing designs.

Alternative touch sensor/solar cell/cover glass stack-up designs.

As with any Apple patent application, it is unclear if the company actually has plans to integrate solar technology into its existing peripheral lineup. Current device designs, with multitouch capabilities and transparent casings, are ideal candidates for such alternative energy solutions, though it remains to be seen if solar conversion technology is up to the task of supplying enough energy, and at ample capacities, to facilitate long-term daily use.

Apple has been researching solar tech for years. Patent filings related to solar-assisted iPod and iPhone recharging date back to 2008, while more recent applications show advanced designs involving device display stack-ups and high-power configurations capable of powering a MacBook.

Last year, The New York Times reported Apple was eyeing solar or wireless inductive charging for its Apple Watch product, then dubbed "iWatch" by media outlets. The company ultimately opted for the latter, though future Watch versions could potentially incorporate some type of light-to-energy conversion technology, at least to help lighten the load on internal battery cells.

Apple's solar-powered computer peripheral patent application was first filed for in January 2014 and credits Matthew E. Lang as its inventor.