Micro-electromechanical systems (MEMS) composed of magnetostrictive and piezoelectric materials can translate information between the electrical and magnetic domains while exploiting mechanical resonance enhancement. Multiferroic MEMS devices such as these can be designed to perform magnetic field sensing and wireless power transfer (WPT) while maintaining device sizes on the order of 0.125 mm 2 . This thesis will focus on the theory, design, and characterization of these MEMS magnetometers and WPT devices.