| abstract |
To provide an electrical device capable of expressing a high ER effect. An electric device comprising an electro-rheological fluid containing particles for electro-rheological fluid filled in a dispersion medium between a pair of electrodes, wherein at least one of the facing surfaces of the pair of electrodes is at least one of them. An electric device having an arithmetic average roughness (Ra) of at least 0.5 μm and less than 300 μm and an average length (RSm) of roughness curvilinear elements of at least 10 nm and less than 100 μm in at least a partial region of the face. 【Selection chart】 None |