Abstract: Based on the concept of intelligent structures, self-coupled damperscomposed of electrorheological (ER) fluids and piezoelectric ceramicsare proposed in this paper. Unlike the conventional ER dampers, theself-coupled dampers employ piezoelectric ceramics to respond theexternal vibration and to provide the electric field for solidification ofER fluids. With a change in the external vibration, the electric fieldchanges accordingly due to the piezoelectric ceramics, resulting in anadaptive control process. The self-coupled dampers have a simple and compactstructure since the high voltage supply and the control system are notinvolved.Two generation products of the self-coupled dampers have been manufactured.Several modifications have been included in the second generationself-coupled damper and both the stability and the reliability of the damperare improved.