Table 8.
Summary of mechanical energy harvester: in vivo examples.
| Year | Organism | Implant site | Mechanical energy source |
Frequency/avail able energy of energy source |
Materials of energy harvester |
Power output |
Power density | Output current |
Output voltage |
Test period | Application | References |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PENGs | ||||||||||||
| 2014 | Bovine | Heart | Heartbeat | 80–120 bpm | PZT | – | 0.18 μW cm−2 | – | 4.06–4.32 V | – | Pacemaker | [301] |
| 2014 | Bovine/ | Lung | Breathing | 12–18 bpm | PZT | – | – | – | 4 V | – | Pacemaker | [227] |
| 2016 | Pig | Ascending aorta | Pulsation of aorta | Systolic BP: 160–220 mmHg, HR: 108 bpm | PVDF | 10–40 nW | – | – | 2 V (Peak V) | – | BP monitoring | [343] |
| 2017 | Pig | Stomach | Gastric motility | – | PZT | – | – | – | 0.06–0.1 V | 48 h | Gastric motility sensor | |
| TENGs | ||||||||||||
| 2016 | Pig | Heart (left ventricular) | Heartbeat | 80 bpm | Kapton-Al | – | – | 5 μA | 14 V | 72 h | Wireless HR monitoring | [305] |
| 2016 | Pig | Heart | Heartbeat | 60–120 bpm | PTFE-Al | – | – | 4 μA | 10 V | 2 weeks | ECG/HR/BP monitoring | [306] |
| 2014 | Rat | Respiratory system (under left chest skin) | Breathing (motion of thorax) | 50 bpm | Kapton-Al | – | – | 0.14 μA | 3.73 V | – | Pacemaker | [77] |
| 2018 | Rat | Digestive system (stomach) | GI motility | 0.05 Hz | PTFE-Cu | – | – | – | 0.1 V (V at 0.3 MΩ) | 15 days | Vagus nerve stimulation for weight control | [93] |
| Electrical generators | ||||||||||||
| 2009 | Human | Ankle | Walking | 1–1.7 Hz | Magnet (NdFeB) | 3.9 μW | 2.6 μW cm−3 | 0.0594 V | – | – | [294] | |
| 2016 | Goat | Circulatory system (left ventricular apex) | Blood circulation | BP: 54.75 mmHg, Blood flow: 2.68 L min−1 | Magnet (NdFeB), ferrite core | 3.4 mW | 1.08 mW cm−3 | 77.4 mA (Peak I) | 7.6 V (Peak-to-peak V) | – | – | [309] |
| AWSs | ||||||||||||
| 1999 | Dog | Heart (right ventricular wall) | Heartbeat | 200 bpm | AWS system[344] with polyvinyl case | 44 μW | – | – | 0.6 (Peak-to-peak V) | 30 min | Pacemaker | [74] |
| 2013 | SheeP | Heart (left ventricular mid lateral wall) | Heartbeat | 90 bpm | ETA 204 (ETA SA, Switzerland) | 16.7 μW | – | – | – | 1 h | Pacemaker | [307] |
| 2016 | Pig | Heart (left ventricle) | Heartbeat | 90 bpm | ETA 204 (ETA SA, Switzerland) | 37 μW | – | – | – | 40 min | Pacemaker | [295] |