Diabetics look forward to the the day when they will no longer have to endure the painful prick of a needle for drawing blood. That day may just have drawn nearer. A team of scientists including chemical engineers from MIT and the University of California, Santa Barbara, have completed the first human tests on an ultrasound device for testing blood sugar levels.

The device uses sound waves to temporarily open up tiny pores in the skin, out through which oozes a small amount of fluid; sugar levels in that the fluid are then measured. Sontra Medical-a Cambridge, Mass., startup launched by UCSB engineer Samir Mitragotri ("100 Young Innovators") and several colleagues-expects to have products ready in three to five years. One possibility: a wrist-watch like device that monitors blood glucose and, when needed, delivers insulin directly through the skin.