In the medical field, several surgical simulators and training platforms have been developed to help novice surgeons improve their surgical skills, as well as perform preoperative planning. In this paper, a haptic platform for surgical needle insertion training gestures is presented. Instead of relying on active actuators, an alternative solution, consisting in passive brakes based on Electro-Rheological (ER) fluids, is proposed, to provide a safe and realistic physical feedback to the physician. This platform generates a passive repulsive force against the user's movement, providing him/her a physical stimulus and, thus, a realistic haptic feedback. The goal of this project is to prove the reliability of ERF-based brakes to simulate the physical resistance of soft tissues against the movement of a surgical needle, in order to train unskilled practitioners in different scenarios. To achieve this objective, a prototype has been built, its kinematic model has been obtained and experimentally validated. The modelling, the bandwidth analysis and the force control scheme of the platform are also presented.