Improved wireless, transcutaneous power transmission for in vivo applications

Electric power, sufficient for many in vivo applications, can be transmitted wirelessly from a small external solenoid (filled with a soft magnetic core), to a novel, magnetoelectric (ME) receiver a few centimeter (cm) inside the body. The ME receiver is a sandwich of electroactive (e.g., piezoelectric) material bonded between two magnetostrictive layers. The electroactive layer may be poled in its plane so that it can function in the stronger g(33) mode (induced voltage parallel to the direction of principal magnetostrictive stress). Preliminary experimental results indicate that a 7 cm long ferrite-filled solenoid (NI approximate to 122 Amp-turns) producing an RMS magnetic field of order 1600 A/m (20 Oe) at the ME receiver (of volume 0.1 CM3) 3 cm from the field source, generates in the ME receiver a power of 200 mW (2 W/cm(3)). The receiver, in turn, generates a power of 160 mW.