Micro in-pipe mobile machines by making use of an electro-rheological fluid

In this paper, first, a three-port micro ER valve (/spl phi/9.8 mm) is fabricated. Static characteristics of the micro ER valve are examined. The valve can produce load pressure change of 0.25 MPa at maximum electric field strength of 5 kV/mm. Secondly, a micro in-pipe mobile machine with the microvalves is fabricated, whose diameter and length are /spl phi/9.8 mm and 34.5 mm respectively. The microvalves control bellows-type microactuators and the in-pipe mobile machine moves like an inchworm. Performances of the in-pipe mobile machine are examined. The maximum average velocity obtained without a load is 0.9 mm/s.