American Semiconductors programmable forearm worn hand and finger heating system (ForeWarm) implements advanced flexible electronic and printed heater materials in an innovative stretchable wearable system. Cold-weather operations diminish comfort and performance while also increasing injury risk. Reduction in hand dexterity and performance can have a major impact on military and civilian operations as many critical tasks rely on hand and finger strength and dexterity. Gloves and mittens that maintain comfort and warmth cause dexterity to degrade by 50%-80% because of the bulky materials and loss of tactile sensitivity. Solutions that increase hand and finger temperatures without gloves are needed to improve occupational and task performance for both military and civilian cold weather workers. The ForeWarm system increases hand and finger temperatures to improve dexterity and finger strength in cold air exposure. A warfighter wearing the ForeWarm system will be able to perform complex tasks bare-handed that are not feasible with bulky gloves. Compared to bare-handed, cold air exposure of 0°C for 4 hours, the goal is to increase hand and finger temperatures by as much as 8°C and improve manual dexterity and finger strength by up to 75% [Castellani et al., 2018]. During the Phase I program, the American Semiconductor team completed the design, layout, manufacturing, and testing of preliminary ForeWarm prototypes. During this Phase I effort, we were able to create, test and deliver demonstration forearm warming systems. The heating elements are manufactured using a low-cost screen printing process. Specialty conductive inks and overcoat dielectrics are printed onto a stretchable substrate material that is then thermal press transferred to the final cloth substrate. Holes are laser cut into the substrate material to provide breathability and moisture wicking away from the skin surface for improved user comfort. The Phase II program will continue the design and manufacturing optimization of these lightweight, low-profile, form-fitting forearm heater systems. In addition, we will be expanding the functionality of the systems by integrating temperature sensors and wireless Bluetooth communication to provide system monitoring and control using a simple smartphone app. The ultimate goal of the Phase II program is delivery of at least 20 completed systems to the US Army while transitioning towards a full, commercially ready manufacturing process suitable for volume production. As in Phase I, DuPont will continue to provide advanced materials and guidance for flexible electronics materials including substrates, heater inks, and insulators. The University of Oregon, led by Dr. Chris Minson, is leading the human performance testing effort to validate the effectiveness and safety of the ForeWarm systems. During Phase I, they completed key preparatory documentation to support the necessary human environmental testing to be conducted in Phase II.
