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Internet of Things (IoT) involves coping with enormous number of distributed devices. This paper introduces three pieces of caching technology as steps towards single-level storage systems that can host and map numerous IoT devices on a single vast address space: 1) a caching mechanism for making solid-state storage appear as huge main memory, 2) speeding up access to resource-limited IoT devices by caching the address translation table of solid-state storage chips, and 3) ad hoc device-to-device data relay, which can be used as effective network caching for mapping IoT devices.

This paper presents a novel control method for wireless power transmission (WPT). The proposed method can maximize the power efficiency only by controlling the voltage ratio between the primary and the secondary side. Experimental measurement results of the prototype system with 3 kW power transmission show the efficiency difference between the proposed control method and the available maximum value is less than 0.3 % even with a large variation of coil-to-coil distance and load voltage. The automatic controller for the proposed method provides the load-following operation, maintaining both constant power and high efficiency, using a WLAN connection.

Nature provides the best models for robots. Inspired by the stick insect, the jellyfish, the butterfly, the lobster, and the inchworm, several kinds of biomimetic locomotions have been proposed, analyzed and investigated in our past researches. Besides the insects and underwater animals, some carnivorous plants which are capable of rapid movement, such as mimosa, the Venus flytrap, the telegraph plant, sundews and bladderworts, are of great interest for the biomimetic robot design. Carnivorous plants, such as Venus flytrap, can be turned on in a controlled manner to capture prey by using their trigger hairs as detecting sensors. In order to implement a Venus flytrap-inspired robotic flytrap, we designed this biomimetic locomotion by using two ionic polymer metal composite (IPMC) actuators. First, we proposed a conceptual structure of the robotic flytrap which consisted of two IPMC lobes and one proximity sensor, and designed the control circuit for the robotic flytrap. Then, we evaluated the deformation and generated bending force of the IPMC actuator by using different applied signal voltages. In addition, we developed a prototype robotic flytrap and utilized a proximity sensor to imitate the trigger hairs of the actual Venus flytrap. The trapping experiment was carried out to verify its feasibility. To evaluate its grasping ability, we measured the maximal grasping payloads with different applied voltages. At last, to reduce the gaps between two IPMC lobes, we improved the robotic flytrap by using three lobes. The experimental results showed a good performance.

Wireless power transfer via magnetic resonance is a technique to realize higher transmission efficiency over a distance of several meters. However, if there are obstacles to the transmission coil, it is difficult to maintain high transmission efficiency. This is caused by variation of matching frequency for the transmission coil brought about by a metal obstacle. This paper evaluates the effect of the transmission performance via magnetic resonance for wireless power transfer when metal obstacles approach the transmission coil. In addition, this paper proposes a procedure for detecting metal obstacles via magnetic resonance.

The transfer efficiency between a transmission coil and a reception coil for wireless power transfer via magnetic resonance is a function of the orientation between the coils. When two coils share a single axis, the transfer efficiency is maximal, but otherwise the efficiency becomes lower. In this paper, a wireless power transfer system via magnetic resonance using a transmission coil array is proposed to improve the transfer efficiency. The transmission coils of the array are excited with appropriate phase weights by transmission circuit, according to the orientation among the transmission coils and the receiving coil. The effect of the proposed system is confirmed by simulation by a method of moment and measurement using a vector network analyzer.