There have been many developments in the field of wireless charging even before Apple announced its inclusion in the iPhones. Various wireless charging standards or technologies have existed such as Powermat, WiTricity, and Energous WattUp, but the predominant standard is Qi-based wireless charging. Qi requires devices to be extremely close to the charging source with a separation distance of less than 40mm. A new startup called 'Pi', however, aims to enable charging from a greater distance between the device and the charger.
The device, also called 'Pi', is shaped like a cone with the top cut off and it could be the first truly contactless wireless charger to be released to the market. The device is based on the same resonant induction technology used in the Qi standard but according to Lixin Shi, the startup's CTO:
“The hard part was figuring out how to make magnetic charging more flexible, multi-device, and extend its useful range. It took us over a year to complete the mathematical proof that makes it all possible.”
The method by which the Pi charger achieves this involves the use of a beam-forming algorithm, enabling the charger to control the shape and direction of magnetic fields. While this may sound somewhat similar to how Wi-Fi has implemented faster data transmission speeds, thanks to the use of multiple-input, multiple-output (MIMO) technology, Shi noted in a prior paper that "there is an intrinsic difference between multi-user MIMO in RF communications and the physics of wireless charging."
The technology was demonstrated by the company co-founders, John Macdonald, CEO, and Shi, at a recent TechCrunch Disrupt event. The demo showed that a Qi-compatible device could be brought within a foot of the charger in order to begin charging. It was also revealed that the Pi device could charge up to four devices simultaneously at full speed within the same range. Macdonald also noted that while more devices could be added it would result in slower charge times. Shi further explained that the resulting slower charge times were a result of the current power limit of 20 Watts, but theorized that future designs could be improved by integrating higher capacity components to boost throughput.
While the co-founders have not ruled out seeing the company's innovation appearing in products from other manufacturers, their main focus is to sell the Pi as a first-party device in its own right. Despite the absence of specific pricing, it is currently expected to hit the market under the $200 mark but the company is offering the first 314 who reserve the product via the company's website a $50 discount code.
At this stage, the Pi wireless charger is expected to ship sometime in 2018.