25/02/2021 Watch: A promotional video for the Wireless Air Charging technology. Credits: Oppo Oppo has given a glimpse at its future offerings at a tech expo in China, including a wireless 'air charger' that will recharge a phone that's anywhere within 10cm of the charging pad. It's the third Chinese company to tease an ability to charge devices in mid-air this year, following Xiaomi and Motorola. At the Mobile World Congress (MWC) event in Shanghai this week, the technology was showcased in use with the Oppo X 2021 rollable concept phone. "Our new Wireless Air Charging technology uses magnetic resonance. Charging begins as soon as the device gets within a few inches of the charging mat, and users can even play games while they wirelessly charge," the company says.