Table III.
Comparison table with State-of-the-Art mm-Scale Wireless Neurostimulators
| This Work | Neuron′17 [11] | ISSCC′18 [13] | TBioCAS′18 [14] | TBioCAS′19 [15] | Nat. Biomed. Eng.′20 [21] | |
|---|---|---|---|---|---|---|
| Application Target | Spinal Cord | Brain | Brain | PNS | Brain | PNS |
| Process (nm) | 180 | Discrete | 350 | 180 | 130 | 65 |
| Wireless Link | Magnetoelectric | Inductive | Inductive | Inductive | Inductive | Ultrasonic |
| Carrier Freq. (MHz) | 0.25 | 13.56 | 60 | 198 | 1180 | 1.85 |
| Implant Volume (mm3) | 8.2 | 98 | 12.2 | 97.5 | 0.009 | 1.7 |
| Stimulation Mode |
Biphasic
Current |
Optical | Optical | Monophasic Voltage | Monophasic Voltage | Monophasic Current |
| Max. Stim. Current (mA) / Resolution (bit) | 1.5 / 5 | N/A | N/A | 0.25 / Fixed | 0.04 / Fixed | 0.4 / 3 |
| Max. Stimulation Charge (nC) | 391 | N/A | N/A | 17.5 | 0.66 | 157 |
| Stimulating Channels | 1 | 1 | 16 | 1 | 1 | 1 |
| SoC Power (μW) | 23.7 | N/A | 300 | 2.7 | N/A | 4 |
| Max. Overall Efficiency (%) @ Distance (mm) |
0.435 @ 0
0.064 @ 30 |
N/A | N/A | N/A | 0.0019 @ 6.6 | 0.06 @ 18 |
| Max. Operating Depth (mm) | 30 | 40 | 7 | 140 | 6.6 | 55 |
| In-Vivo Test Model | Hydra | Rat | Rat | Rat | Rat | Rat |