Yoshiharu Kagami

Motion design of a starfish-shaped gel robot made of electro-active polymer gel

Abstract This paper proposes a method to generate novel motions of mollusk-type deformable robots made of electro-active polymer gel. Simulation and experimental results show that large transformations can be obtained with multiple electrodes in a planar configuration. We have designed a starfish-shaped gel robot that can turn over using spatially varying electric fields.

Chemomechanical bending behaviors of ionizable thin films with gradient network-size

An ionizable thin film with gradient network size in direction of thickness was prepared using 10-undecenoic acid(UA) by plasma polymerization. Gradient structure in the network size was estimated by values of relative diffusion coefficient of ferocian ions through the film. The obtained film was found to show chemomechanical behavior. The film bent in alkaline solution due to anisotropic swelling in direction of thickness and recovered to the original shape in acid solution.

Dynamics of gel robots made of electro-active polymer gel

This paper proposes a model for predicting the dynamic motions of elastic robots made entirely of electro-active polymer gel. The requirement is that both the active and passive deformations be described simultaneously. Active deformations arise from a generated stress, while passive deformations are due to external forces, such as gravity and friction. We represent both in the same framework, considering them as the result of either electrochemical or mechanical interaction between the gel robot and the environment. We evaluated the model by comparing the results obtained through simulations and experiments using prototype gel robots. One experiment involved hitting an external object, and the other involved bending while resting upon a surface. We present an overview of the model, with a discussion of the experimental results and future work.

Shape design of gel robots made of electroactive polymer gel

We propose a novel method to design the shape of small elastic robots made entirely of electroactive polymer (EAP) gel. The gel operates as actuators in microsystems and can facilitate bending motions. In this paper, we bring out directional deformation from originally bending type polymer driven by electric fields. The key idea is to partially reduce the structural flexibility through shape design. To achieve directional motion, we designed gels with wave-shaped surfaces. The thick parts and thin parts of the surface are distributed in either one or two directions. We developed a mollusk type gel robot which shows bi-directional motion. In this way, we propose the method to design the desired deformation response by shape design of the material in advance. This technique is especially suited for MEMS consisting of soft materials.

Optical storage effects in dye polymeric gel

The polymeric cross-linked hydrogel doped with dye 4- nitroaniline was prepared. The nonlinear optical properties of this material has been studied. The optical storage effects and the dynamic lens effects in this dye doped hydrogel under laser radiation have been observed. It is reasonable to show that this dye doped polymer get will find some applications in optical signal processing.

Electrical Conductivity and Gas Response of Plasma-Polymerized Titanium Containing Organic Thin Films.

チタニウムテトライソプロポキシド(TIPP)を出発物質として高い導電率を示すチタソ含有プラズマ重合膜を合成し,導電率の変化に基づくガスセソサーとしての機能につい七調べた。その結果,プラズマ重合によって合成したチタン含有有機薄膜は150～300℃ の温度範囲で,メタノール,エタノール,1-ブタノール,t-ブチルアルコール,アセトンなど,酸素と反応する有機可燃性ガスが存在すると,膜の漕電率が速やかに増大する現象を見いだし,これを利用すると導電率の増加により有機可燃性ガスを定量的に測定できることが明らかとなった。このセンサーの応答機構は膜表面の酸素の吸脱着により,導電率が変化するためであると考えられ,その機構について議論した。