Hiroki Takashima

Design and characterization of high-performance contactless gripper using spiral air flows

We present a MEMS-based contactless gripper with arrayed spiral air flows, aimed at the mitigation of the flow-induced vibration of the levitated object. For non-contact levitation as applied to the robot end-effector, the air flow-based handling system has attracted increasing attention due to the simplicity of the structure and its control. Our design is based on the concept of distributed forcing by arrayed spiral-flow chambers. In each chamber, a spiral flow is generated, which effectively induces the attraction force by negative pressure. Our device has extremely thin structure, compatible with MEMS-based fabrication. In the present study, we fabricate proof-of-concept devices, and examine the basic characteristics. We demonstrate the promising performance of the present gripper through force-measurement experiments. Design considerations by CFD analysis and a simplified analytical model of the attraction force are also presented. The present results support the effectiveness of our strategy, and it is suggested that the arrayed structure with spiral-flow chambers and suction hole is much effective for obtaining desired attraction force while enhancing the holding stability.

5-inch-size contactless gripper using arrayed spiral air flows

We present a novel application of the MEMS technology to a contactless gripper using arrayed spiral air flows, aimed at the mitigation of flow-induced vibration of levitated objects. For robot end-effector dealing with fragile objects such as silicon wafers and solar panels, we employ an air flow-based gripping technique with continuous air-blowing, which would enable damage-free handling without contamination. We design the gripper based on the concept of distributed forcing with arrayed spiral-flow chambers and suction holes. In this paper, we show the basic characteristics of proof-of-concept devices, and extend our proposed concept to design and fabricate enlarged grippers in a size of 5 inch square. It is shown that the attraction force is successfully obtained by the negative pressure of a spiral flow in each chamber, and that suction holes play an important role in eliminating the interaction between the neighboring chambers and narrowing the holding gap so as to increase the force density over the entire object.

Micro spinning nozzle having 3D profile for fiber generation with spiral air flow

This paper presents a novel application of MEMS technology to the miniaturization of air-flow type fiber-generation technology. In Murata vortex spinning (MVS) machine, a nozzle for continuous air-jet blowing, which is the key component in producing fibers with distinctive nature, is equipped in the spinning chamber. With the intention of extending the MVS principle to smaller-scale fiber generation, we propose MEMS-based nozzles having 3D profile, transformed from conventional oblique jet holes with straight cylindrical shape. We design the nozzle geometry using computational fluid dynamics (CFD) simulations, and examine the applicability of presently fabricated nozzles to fiber generation through simplified experiments.