Variable Compliance

• Open-loop - totally passive, but limited to voltage- or shape-changing to set spring constant
• Closed-loop - requires knowing muscle position in real-time
  • To do this, I need
    • a low-voltage signal of some limited bandwidth (what bandwidth?) with an overlaid HF signal
    • high voltage supply with the bandwidth to pass the HF signal
    • a high-pass filter to measure the phase lag of the HF signal? or simply the attenuation?

Variable Damping

• Need high-voltage variable resistances, possibly through turning on resistors using VMI optos.