A low drop-out regulator for subcutaneous electrical stimulation of nanofibers used in muscle prosthesis

A low-dropout regulator (LDO) for the electrical stimulation of ionic electroactive polymers (iEAPs) used in subcutaneous muscle prosthesis is presented. The special requirement of the application and the characteristics of iEAPs impose several design challenges for the stimulator. In this paper, these challenges are discussed and solutions are provided. The proposed LDO, designed and simulated in IBM 0.13-μm CMOS technology, uses external-capacitor-less architecture to enable a fully on-chip solution for providing stable stimulation across a wide load range, as required by the properties of iEAPs. The LDO also offers precise line and load regulations, as well as improved power supply rejection (PSR) to suppress the supply noise when the LDO is powered up through wireless power transfer (WPT) links. Simulation results are provided suggesting that the proposed LDO can be used as a stable and precise stimulation source for controlling the movement of iEAPs with a potential application in muscle prostheses.