This research aims to develop a portable haptic master hand with 20 degrees of freedom (DOF). Master hands are used as haptic interfaces in master-slave systems. A master-slave system consists of a haptic interface that communicates with a virtual world or an end-effector for tele-operation, such as a robot hand. The thumb and fingers are usually modeled as a serial linkage mechanism with 4 DOF. So far, no 20 DOF master hands have been developed that can exert perpendicular forces on the finger phalanges during the complete flexion and extension motion. In this paper, the design and development of two concepts of a portable 4 DOF haptic interface for the index finger is presented. Concept A is a statically balanced haptic interface with a rolling-link mechanism (RLM) and an integrated constant torque spring per DOF for perpendicular and active force feedback. Concept B utilizes a mechanical tape brake at the RLM for passive force feedback. The systematic Pahl and Beitz design approach is used as an iterative design method.