Smart exercise device using triboelectric self-powered sensor for high intensity interval training (HIIT)

High intensity interval training (HIIT) where periods of high intensity exercise are interspersed with periods of low intensity exercise or rest, packs a high-power workout into a short period resulting in higher oxygen uptake compared to other training methods. Commercial equipment used for such exercise protocols either requires manual adjustment or provides pre-programmed options without adapting to the user's performance. It would be much more convenient if the exercise equipment could detect how well the user is exercising and automatically adjust the training intensity level. Thus, in this work, we developed a smart exercise device using a triboelectric nanogenerator (Exercise-TENG). The device utilized the input torque increasing characteristic of the planetary gear system. As the subject operated the Exercise-TENG, energy harvested by the TENG was stored into a capacitor. The level of energy harvested into the capacitor was both an indicator of the user's exercise performance, and a trigger to increase or decrease the input torque required to operate the device. Furthermore, the user could be motivated to exercise by providing real-time feedback on the amount of energy harvested via a LabVIEW interface. Finally, we conducted HIIT bicep curl and triceps extension exercises using the Exercise-TENG and measured muscle activation levels to verify its effectiveness. Compared to other exercise devices, Exercise-TENG is a personalized solution that automatically adapts to the users' abilities with a unique motivation element especially needed for patient rehabilitation. We expect that our device will be a viable product for home exercise or patient rehabilitation applications.