Wearable sensor

A wearable electronic apparatus for monitoring physiological and/or brain signals, the apparatus comprising:

• at least one assembly of layers, the assembly comprising:
• a first flexible polymer thin film substrate layer,
• a second flexible polymer thin film passivation layer comprising at least one opening, and
• a conductive layer sandwiched between the first flexible polymer thin film substrate layer and the second flexible polymer thin film passivation layer, wherein the second flexible polymer thin film passivation layer shields the first flexible polymer thin film substrate layer and the conductive layer from electromagnetic interference;
• at least one sensor for monitoring physiological and/or brain signals, provided on the conductive layer, wherein the at least one opening corresponds to a position of the at least one sensor, such that when the apparatus is configured to be attached to a user's skin, the at least one sensor is in contact with the user's skin;
• and
• circuitry coupled to the at least one sensor, the circuitry comprising:
• a wireless communication module for transmitting sensor data to an external device, and
• at least one integrated circuit chip, wherein the conductive layer comprises a plurality of conductive tracks for coupling the at least one sensor to the at least one integrated circuit chip.