As the relentless miniaturization of semiconductor devices strains the physical laws that once governed them, researchers in Chennai have found a way to turn a constraint into a capability. By designing a tunnel field-effect transistor with an inverted T-shaped body and dual metal gates, they have not only tamed the short-channel effects that haunt scaled devices, but also fashioned the transistor itself into an ultrasensitive biosensor — one that detects biological molecules without the need for chemical labels. The work, grounded in a rigorous analytical model derived from first principles,