A wearable sensor

Assembly of layers 10 comprising first polymer thin film substrate layer 100, second flexible polymer passivation layer 103 and a conductive layer 101 sandwiched between the two. The second polymer layer shields first layer and the conductive layer. There is at least one sensor on the conductive layer coupled by conductive tracks, which may be flexible, to associated circuitry including a wireless communication module and at least one integrated circuit chip. The second layer may have an opening to allow the sensor to make contact with the skin and an adhesive layer to attach it to the skin. The thickness of the first and second layers may be 10 microns and the conductive tracks may be 2 microns. In one embodiment the assembly of layers may be folded with either a single [Fig. 2a] or multiple folds. In another, two assemblies of layers may be stacked [Fig. 3a]. In a third embodiment, there may be a flexible cable for electrically connecting the assembly of layers to a rigid printed circuit board [Fig. 4b].