Clawed Miniature Inchworm Robot Driven by Electromagnetic Oscillatory Actuator

In this research we propose a novel inchworm robot, which is composed of an Electromagnetic Oscillatory Actuator （EOA） and claws. The EOA consists of a yoke, a magnet, and a coil. The overall robot size is 12.2 mm x 11 mm x 9 mm （length x height ~ width）. The locomotion of the robot is achieved by different amounts of slips when the robot stretches and contracts its front leg. To realize locomotion, the working conditions were calculated theoretically and the calculated input signal was applied to the robot. The performance of the inchworm robot was evaluated experimentally with varying input voltages and frequencies. A simple op-amps based driving circuit was used to provide a square-wave input. Travel speed, average distance per step of the robot, and moving distance of the leg and body at each step were measured. The maximum travel speed was 36 mm-s-1 at 30 Hz, which validates our simple locomotion strategy experimentally.

A Miniaturized Tadpole Robot Using an Electromagnetic Oscillatory Actuator

In this paper, we propose a miniaturized tadpole-like robot using an electromagnetic oscillatory actuator. The electro- magnetic actuator has a simple structure with a moving-magnet type and the body size is 13 mm （length） × 11 mm （height） ×10 mm （width）. A tail has the thickness of 100 μm and the length of 20 mm which is twice of the body-length （BL）. The tail attached to the oscillatory actuator generates undulatory propulsion for the forward swimming. Moreover, the tadpole robot enables the change of the direction by controlling input signal pattems applied to the oscillatory actuator. Prototypes of the tadpole robot have been manufactured and the thrust force and swimming speed are measured to evaluate the performance of the biomimetic robot in water at various tail-beat frequencies. The maximum thrust force is 42 mN at the tail-beat frequency of 30 Hz with voltage of 3 V, enabling the tadpole robot to swim at the speed of 210 mm·s^-1 （6 BL·s^-1）. The tadpole robot can also change its moving direction with the angular velocity of 21 deg·s^-1 at the half pulse pattem of 30 Hz.

A Designated Query Protocol for Serverless Mobile RFID Systems with Reader and Tag Privacy

Recently, a new type of Radio Frequency IDentification （RFID） system with mobile readers is introduced. In such a system, it is more desirable for mobile readers to identify tags without a back-end server, and thus it is frequently referred as a serverless mobile RFID system. In this paper, we formalize a serverless mobile RFID system model and propose a new encryption-based system that preserves the privacy of both tags and readers in the model. In addition, we define a new adversary model for the system model and show the security of the proposed system. Throughout comparisons between ours and the other alternatives, we show that our proposed system provides a stronger reader privacy and robustness against a reader forgery attack than the competitors.