Selective signal transmission to inlaid microcoils by inductive coupling

Inductive links are widely used to power medical implants, but are not suited to transmitting low frequency waveforms. Here, using amplitude modulation, such waveforms are transmitted via an integrated receiving coil and a passive demodulator. An "inlaid electroplating" process is used to fabricate microcoils of small resistance to obtain enhanced output. As our inductive link resonates at a frequency specific to the secondary microcoil, selective signal transmission is demonstrated with frequency-multiplexing input. Further, combining two coils with switching transistors, biphasic pulses are produced at the load, which has potential applications for biomedical electrical stimulations.