Piezoresistive Nanowire Biosensor

A functionalised silicon nanowire is anchored at one end like a tiny diving board. As target molecules drift in and bind to its surface, they change the local surface stress and bend the wire by a fraction of a nanometre — and because silicon is piezoresistive, that bend measurably shifts the nanowire's electrical resistance. This simulator models the full chain: Langmuir adsorption kinetics decide how fast molecules bind and saturate the surface, Stoney's equation converts the resulting surface stress into curvature and strain, and the piezoresistive gauge factor converts strain into a real ΔR/R you can read off live. Switch between p-type and n-type doping to see the resistance response flip sign, and shrink the nanowire's thickness to watch sensitivity climb — exactly the trade-off that makes nanoscale sensors so much more responsive than their microcantilever ancestors.