Verily, the Alphabet company formerly known as Google Life Sciences, has been working for several years on a device that is designed to collect blood painlessly using a system of exploding micro-needles and magnets. The Silicon Valley team, which is run by Verily's chief technical officer Brian Otis, has gone as far as to produce a working prototype. It's exploring several possible form factors for the device, including a watch. The needles would "explode" into the wearer's skin, then the magnets would retract them for future uses. Several sources aware of the company's plans say the device is still many years away from production and faces significant scientific, technical and regulatory hurdles. These people described it as a long-term project akin to other so-called "moonshots" that Alphabet is working on.

The people declined to be named as the project has not been publicly announced. Verily has not yet been able to line up the necessary development partners in health and life sciences, despite several efforts. There would also be a high bar to prove to the U.S. Food and Drug Administration that such an approach is safe and effective for patients.

What would it be used for?