This won't hurt

SpectRx and Altea Technologies of Atlanta, Georgia are patenting
(WO 00/03758) a way of using tiny explosive charges to inject drugs, take blood
samples or even etch tattoos. In place of a needle the syringe uses a blunt
probe tipped with a pyrotechnic mixture. The explosion produces a tiny opening
in the skin through which fluids—including drugs or tattoo dyes—can
be pushed or sucked. The flash of a laser diode or an electrical pulse triggers
the charge. It all happens in 10 milliseconds, so the skin temperature never
rises above 40 °C—well below the human pain threshold. The…