A flexible electro-rheological microvalve (FERV) based on SU-8 cantilever structures and its application to microactuators

On purpose to realize flexible electro-rheological microactuators (FERMA), this paper presents a MEMS-based flexible ER microvalve (FERV) by integrating thin SU-8 cantilever structures and the SU-8-sandwiched microfluidic channels for homogeneous ER fluids. The structure of the FERV is the fluidic channel-embedded cantilever. The FERV is successfully fabricated with 5 mm in length, 2.4 mm in width and 0.2 mm in thickness and the bending of the FERV shows enough flexibility. The static and dynamic characteristics of the FERV are experimentally investigated. The controllable pressure change rate of the FERV is about 70% of the supply pressure and the step-up response time is about 0.25 s. There is not such a difference of the static and dynamic performance between a straight FERV and a bent FERV, showing that bending does not affect the characteristics of the FERV. A bellows-type FERMA is realized and its elongation is 4.8 mm. The experimental results prove the feasibility of FERMA.