Abstract: A wrist-worn device includes a device housing, an electrochemical sensor, control circuitry, optional tamper sensors, and a water-absorbing material. The device housing includes an upper housing and a lower housing attached to the upper housing. The lower housing includes a top wall and a circumferential side wall. The top wall defines a first access opening. The device housing also includes a wrist piece having a first face and a second face that defines a trench in the first face that protrudes from the second face as a closed curve-shaped protrusion. The lower housing and the wrist piece cooperatively form an amplification chamber. The wrist piece also defines a plurality of vent holes that allow transdermally emitted ethanol to enter the amplification chamber. The control circuitry is configured to receive measurements and to calculate transdermal alcohol concentrations from the electrochemical sensor.

Abstract: A wrist-worn device includes a device housing, an electrochemical sensor, control circuitry, optional tamper sensors, and a water-absorbing material. The device housing includes an upper housing and a lower housing attached to the upper housing. The lower housing includes a top wall and a circumferential side wall. The top wall defines a first access opening. The device housing also includes a wrist piece having a first face and a second face that defines a trench in the first face that protrudes from the second face as a closed curve-shaped protrusion. The lower housing and the wrist piece cooperatively form an amplification chamber. The wrist piece also defines a plurality of vent holes that allow transdermally emitted ethanol to enter the amplification chamber. The control circuitry is configured to receive measurements and to calculate transdermal alcohol concentrations from the electrochemical sensor.

Abstract: A method for fabricating an electrochemical sensor material includes positioning sheets of molded graphene nanoplatelets on each side of a proton exchange membrane and integrating graphene nanoplatelets into regions of the proton exchange membrane adjacent its surfaces by applying heat to increase the temperature of the proton exchange membrane to its glass transition temperature and applying compressive pressure to press a portion of each sheet of molded graphene nanoplatelets into the softened polymeric material of the proton exchange membrane. Following application of heat and pressure, the proton exchange membrane is cooled and excess graphene material is exfoliated. Electrochemical sensor components are cut from the material and electrochemical devices and systems are constructed therefrom.