Table III.
Benchmarking of mm-Sized. Wirelessly Powered Optogenetic Interfaces
| Publication | [17] | [18] | [19] | [20] | [21] | This work | |
|---|---|---|---|---|---|---|---|
| Technology | COTS | COTS | COTS | 0.35-μ CMOS | 0.18-μ HV BCD | 0.35-μ CMOS | |
| Wireless power, operating Freq. | RF, 1.5 GHz | RF, 2.9 GHz | RF, 13.56 MHz | Photovoltaic | Ultrasound, 1.314 MHz | RF, 60 MHz | |
| Number of stim. channels | 1 | 4 | 1 | 1 | 4 | 16 | |
| Max. ILED (mA) | - | - | 20 | 5 | 5 | 10 | |
| Light intensity (mW/mm2) | 1-60 | 30 | 1-50 | 15 | 1.4-23 | Up to 10 | |
| Stimulation Power eff.** % | 19* | - | - | 10.7* | 50.3** | 37.5** | |
| efficiency * Optical eff.*** % | - | - | 30.7*** | 62.5*** | |||
| Device size (mm3) | 10-25 | 125 | 9.8 mm diameter, 1.3 mm thickness | 1.3×1.3 ×(0.6-1.0) | 2×3×6.5 | 2.5×2.5×1.5 (in vivo) | 8×14×2 (in vivo) |
| Device weight | 20-50 | 220 | 30 | 2.3 | 78 | 15 mg (in vitro) | 0.5 g (in vivo) |
| Stim. proper Ctrl | No | No | No | No | Yes | Yes | |
| In vivo experiments | Yes | Yes | Yes | No | Yes | Yes | |
*
Stim. eff. = power eff. × optical eff.
**
Power eff. = rectifier eff. × LDO eff.
***
Optical eff: output light power divided by input power.