An integration of micro devices system and wireless power transmission (WPT) technology offers a great potential to revolutionize current health care devices. The system integration of wireless power transmission devices with smart microsensors is crucial for replacing a power storage devices and miniaturizing wireless biomedical systems. Our research goal is to replace battery power supply with an implantable millimeter-wave rectenna. Recently, a hat system with a small millimeter-wave antenna which can feed millimeter-wave power to thin-film rectenna array embedding Schottky diodes was introduced for neural sensing and stimulation applications. In order to prove the design concept and investigate wireless power coupling efficiency under the system design, near-field wireless power transmission was studied in terms of wave frequency and distance. Also, in this paper, we will present the influence of biological objects to the wireless power transmission, simulating the experimental conditions of human objects for future medical applications.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.