Bidirectional current-voltage converters based on magnetostrictive/piezoelectric composites

We report a power supply-free, bidirectional electric current-voltage converter based on a coil-wound laminated composite of magnetostrictive alloy and piezoelectric crystal. An electric current applied to the coil induces a magnetic field, resulting in an electric voltage from the composite due to the direct magnetoelectric effect. Conversely, an electric voltage applied to the composite produces a magnetic induction due to the converse magnetoelectric effect, leading to an electric current from the coil. The converter exhibits excellent linear relationships between current and voltage. Compared with traditional current/voltage converters made by operational amplifiers, the advantages of the proposed device include low cost, no power consumption, and bidirectional conversion.