Fully-polymeric NEM relay for flexible, transparent, ultra-low power electronics and sensors A fully-polymeric nano-electro-mechanical (NEM) relay based on a conductive polymer, Poly(3,4-Ethylenedi oxythiophene):Polystyrene-Sulfonate (PEDOT:PSS) and dielectric polymers is proposed for the first time to enable flexible, transparent, ultralow-power electronics and sensors, and the first functional prototype fabricated using a five-mask low-thermal-budget process is demonstrated. The prototype shows zero off-state leakage current, abrupt on/off switching, complementary switching behavior, and relatively high on/off current ratio. Exploiting the water-absorption behavior of the polymers, the potential use of the relay as a biochemical sensor is also demonstrated.