Atlanta-based Altea Development is creating what has long been a diabetic’s fantasy: a system that delivers insulin through skin patches rather than by injection. First the patient places on his or her skin a handheld device bearing an array of tiny filaments. Each of the filaments delivers a three-millisecond burst of heat that vaporizes dead and dying cells and creates a micropore in the skin’s outer layer, which normally blocks absorption of large molecules such as insulin. Because the pulse of heat is too brief to affect the underlying living cells, the process is painless. The patient can then replace the device with an insulin-filled patch; for the next 24 hours, the insulin diffuses into the skin and is absorbed into the bloodstream. Alan Smith, Altea’s vice president of research, says that preliminary tests with human subjects have been successful, and he expects more extensive clinical trials to begin by the end of this year.