Electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is possible to develop a novel robot finger/hand integrated with a pump and a tank by using ECF as a power source. The purpose of this study is improvement of the ECF robot finger we have been proposed. First, we propose a new type ECF jet generator which is a micro power source of the robot finger. Next, we characterize a flexible finger which newly has a strain gauge to detect a displacement of the finger. Finally, we develop a new robot finger which mainly composed of the ECF jet generator and the flexible finger, and demonstrate that the performance of the robot finger was improved.