Triboelectric nanogenerators and piezoelectric nanogenerators for preventing and treating heart diseases

Heart diseases pose a serious threat to human health, and their incidence has been increasing in recent years. In past decades, many strategies have been developed to decrease the mortality and morbidity of heart diseases, among them, strategies involving cardiac electronic devices (CEDs) have been effective in treating and preventing heart diseases. To allow the CEDs to work continuously without the need to replace batteries and to meet the requirements of convenience and comfort in the process of use, nanogenerator (NG)-based CEDs were proposed, widely studied, continuously optimized in recent years owing to their advantages of small dimensions, self-powering ability, and good biocompatibility. In this review, recent improvements of NG-based CEDs of two typical types (i.e., triboelectric nanogenerator [TENG] and piezoelectric nanogenerator [PENG]) and their structures and functions are summarized and discussed. The demands, remaining challenges, and future development trends of NG-based CEDs are also discussed.