Tiny stamps for tiny sensors
Advances in microchip technology may someday enable clinicians to perform tests for hundreds of diseases — sifting out specific molecules, such as early stage cancer cells — from just one drop of blood. But fabricating such “lab-on-a-chip” designs — tiny, integrated diagonistic sensor arrays on surfaces as small as a square centimeter — is a technically challenging, time-consuming and expensive feat. Now, researchers at MIT have come up with a simple, precise and reproducible technique that cuts the time and cost of fabricating such sensors. Nicholas Fang, associate professor of mechanical engineering, has developed an engraving technique that etches tiny, nano-sized patterns on metallic surfaces using a small, voltage-activated stamp made out of glass. Fang says the engravings, made of tiny dots smaller than one-hundredth the width of a human hair, act as optical antennae that can identify a single molecule by picking up on its specific wavelength. “If you...