Mode-Coupled Synergistic Triboelectric Device for Biomechanical Applications

Triboelectric generators (TEGs) are extensively utilized for transducing biomechanical energy into electrical energy for harvesting and sensing applications. The distinct motions of the human body can be categorized broadly into rotation/twist, vertical, and lateral translations, and tactile stimuli. To capture the biomechanical energy associated with all such actions, TEGs based on distinct modes can be employed. However, the use of multiple distinct TEG units increases the deployment expenses and complexity. The proposed work envisions a novel strategy for harnessing biomechanical energy using a synergistic triboelectric device that incorporates all four fundamental triboelectric operation modes in a single topology. The TEG modes generate a peak output power of 16.6 [contact separation (CS)], 7.6 [sliding (SL)], 12.1 [single electrode (SE)], and
$6.24~\mu \text{W}$
[freestanding (FS)] for charging batteries and driving commercial electronics. As an application of the proposed device, the electrical signal generated in each TEG mode in response to various ankle movements is recorded. A novel application of this device for the selective enhancement of a triboelectric mode in complex biomechanical activities involving both major and minor biomechanical stimuli is presented. The minor stimuli can precharge the triboelectric layers of the TEG mode corresponding to the major stimulus, thereby enhancing the harvesting and sensing capabilities of the device. The enhanced performance of the dominant triboelectric mode can be used for powering several wearable applications.