Nobody likes being jabbed with a needle. But how to deliver medications without pain? One solution: arrays of tiny silicon needles. Georgia Institute of Technology researchers Mark Prausnitz and Mark Allen fabricated a prototype array 10 millimeters square, bristling with silicon needles 150 microns long. Such needles make a microscopic hole in the skin's outer layer, which is devoid of nerve endings. Such devices could offer the convenience of skin patches but administer a much wider variety of drugs than the few (such as nicotine) that are absorbed directly through the skin.

The microneedles are particularly promising for the delivery of new biotechnology-derived drugs that are destroyed by digestion and cannot be taken orally. These drugs generally must be administered frequently, rendering conventional hypodermic injection impractical. Ultimately, the arrays could be programmed so that, for example, a microprocessor could sample blood-sugar levels and administer insulin in just the right doses.