Optical Tweezers are considered one of the most suitable techniques for biological tasks, however the lack of automation make this technology less accessible. We present here a new 3D force sensing method with high bandwidth (up to 10Khz) which can allow implementing complex robotic approaches. Proposed technique uses high speed image tracking with nano-metric resolution in 3 directions. Its capabilities are demonstrated in a teleoperated 3D manipulation scenario with a haptic user interface, where naive users performed direct in vitro haptic exploration of isolated Red Blood Cells inside a Petri dish.