1 Subjects: “...Energy harvesting...”

2 Subjects: “...low-frequency vibration energy harvesting...”

3 Subjects: “...energy harvesting...”

4 Subjects: “...thermal energy harvesting...”

5 Subjects: “...electrostatic vibration energy harvesting...”

6 Subjects: “...piezoelectric vibration energy harvester...”

7 Subjects: “...energy harvesting...”