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 known that a strong ECF jet is generated under nonuniform electric field, for example, the field with a pair of needle and ring electrode (a needle-ring electrode pair). This study introduces the ECF jet to develop a novel robot finger. First, we propose a concept of novel robot finger driven by ECF jet. The robot finger mainly consists of a bending actuator, an ECF tank, and ECF jet generators. Next, we characterize the bending actuator and the ECF jet generator. Finally, we investigate the characteristics of the robot finger. The length, the diameter, and the mass of the robot finger are 34.2mm, 12mm, and 3.8g, respectively. The robot finger can generate force of 0.28N and bend approximately 70deg.