Fujitsu’s vein sensor measures just 29mm wide, 11.2mm tall, and 29mm thick. It could be added to laptops or even cell phones in the future. The sensor scans a person’s hand to determine who they say they are and cross-referenches them with stored images of the user’s hand. A wave over the sensor is enough to identify the person by snapping up to 20 photos of the person. It’s not necessary to touch the sensor, with a small wave over it being enough to do the same thing.”]
Source: https://gizmodo.com/worlds-smallest-vein-sensor-reads-veins-for-secure-acce-5793434