The Painless Needle

A mosquito bite barely registers, and that is no accident. Its mouthparts are serrated, touching skin at only a few tiny points, and they vibrate as they push in, so the skin parts instead of tearing.

Engineers are copying that trick to build hair-thin needles that slip in with far less force and far less pain. For someone with diabetes facing a lifetime of daily jabs, a needle they barely feel is not a gimmick; it is daily relief.