For many diabetics, life is managed one insulin-filled syringe after another. But if an new experimental wristband is further refined, they may be able to ditch the needles for good. The device is a clear rubbery band embedded with sinuous traces of gold and gold-doped graphene drug delivery system and sensors. It senses changes in the wearer’s sweat and, on a wirelessly connected device like a smartphone, correlates that with changes in blood glucose level. When necessary, it delivers a dose of the drug metformin, which primarily suppresses glucose production in the liver, via an array of microneedles. Details of the new device were published this week in the journal Nature Nanotechnology.