Fig. 4

In vivo energy harvest and electrical characterization. a, b The iTENG implantation process in animal experiments. c, d The iTENG was driven by the diastole and systole of the heart. e Schematic of in vivo experimental electrical characterizations. f Charging curve of a 100 μF capacitor charged by iTENG. g In vivo open-circuit voltage, transferred charge, short-circuit current of the iTENG and simultaneously recorded electrocardiography (ECG). h In vivo output open-circuit voltage and simultaneously recorded ECG signals. i The relationship between ECG signals and the voltage of a 1 μF capacitor charged by iTENG. j Statistics-analysis of minimum voltage, maximum voltage, and the voltage difference. k Statistics-analysis of minimum transferred charge, maximum transferred charge, and the transferred charge difference. Source data of j, k are provided as a Source Data file. All data in j, k are presented as mean ± s.d.