Photos: A new system for painless shots

You are staring at what could be the future of injections. The Tyndall Institute in Cork, Ireland, has come up with a technique for making arrays of microneedles that it says result in cheaper, more effective medical patches. Microneedles penetrate the skin but don't go far enough down to touch nerves, resulting in painless injections.

Tyndall essentially takes a silicon wafer and bathes it in hot potassium hydroxide in a tightly controlled manner. (The wet etching is stopped and started several times.) The chemicals etch away silicon until you are left with eight-sided needles.

Some large pharmaceutical companies currently make microneedle patches. The needles, however, are made of metal, which is getting more expensive. Other researchers are working on silicon microneedles but use a dry etch process, which results in more brittle needles. The needles in the wet etch patch are more robust, claims Conor O'Mahony, who is trying to develop patches and applications for microneedle arrays at Tyndall. The sides of the microneedles from the wet etch process are also smooth, so they don't pull tissue out. That is important because if tissue cells get pulled out, they can drag medicine with them.