Table 2.
Comparison of Power Generation Techniques for Implantable Biosensing Applications.
| Method of Micro-generation | Advantages | Disadvantages | Power Generation Potential | Input Energy Source | Applicability to implantable applications |
|---|---|---|---|---|---|
| Photovoltaic | Regenerative, abundant power source. | Efficiency and output is tied to light intensity. | 500 μW [11]–1 W [12] | Light/Photons | Applicable where sufficient light intensities are present. Not Applicable otherwise. |
| Thermovoltaic | Regenerative | Size Requires large temperature difference for efficient generation. | 4.5 μW–100 μW [16] (Thermopiles) 0.8 μW [22] (P3 Micro-heat engine) | Ambient or supplied heat. | Applicable |
| Micro Fuel Cells | Can be regenerative. Reasonable energy density. | Hydrocarbon fuels (highest energy) are not biocompatible. | 50 μW/cm2–430 μW/cm2 [25] (Glucose based) 9 mW/cm2–750 mW/cm2 [29,35] (Hydrocarbon Based) | Supplied fuels such as Glucose or Hydrocarbons | Glucose based micro fuel cells are applicable. Hydrocarbon micro fuel cells are not. |
| Electrostatic | Can be regenerative with electrets and charge pumps. | Requires energy to produce energy. | 20 μW/cm2–116 μW/cm2 [4] (In-plane gap closing type) 100 μW/cm2 [45] (out-of-plane type) | Ambient or supplied vibration. | Applicable |
| Electromagnetic | Regenerative High power Density. | Poor length-scale based scaling. | 12.5 μW [52] (Cantilever) 45 nW [50] (Membrane) 386.46 μW [53]–6.6 mW [54] | Ambient or supplied vibration. | Applicable |
| Piezoelectric | Regenerative High power density. Customizable | Possible bio-compatibility issue. Highly frequency dependant. | 375 μW [60] (Bimorph) 10 mW [69] (Membrane) 2.7 mW/cm3 [66] (ZnO Nanowire) | Ambient or supplied vibration. | Applicable |