A self-powered HMI that is also waterproof

Over the past few decades, human-machine interface (HMI) technologies, especially driven by the demands of wearables, have progressed rapidly—into smaller, lighter, more efficient, more robust forms. Today, we also have various self-powered HMIs, using piezoelectricity and triboelectricity, for example, for power generation. Despite these advances, most wearable HMIs still remain relatively defenseless to moisture, such as sweating and weather conditions.