Abstract-This paper presents a novel miniaturized force-indentation depth (FID) sensor designed to conduct indentation on soft tissue during minimally invasive surgery. It can intra-operatively aid the surgeon to rapidly identify the tissue abnormalities within the tissue. The FID sensor can measure the indentation depth of a semi-spherical indenter and the tissue reaction force simultaneously. It make use of with fiber optical fiber sensing method measure indentation depth and force and is small enough to fit through a standard trocar port with a diameter of 11 mm.The created FID sensor was calibrated and tested on silicone block simulating soft tissue. The results show that the sensor can measure the indentation depth accurately and also the orientation of the sensor with respect to the tissue surface whilst performing indentation. . I. INTRODUCTIONThere ). Distinct advantages of these robotic systems include high distal dexterity, enhanced 3D vision, motion scaling and tremor filtering as well as direct hand-eye coordination eliminating reversed tool motions. These advances result in improved ergonomics and also allow complex surgical procedures, which are usually difficult to be conducted by conventional minimally invasive means such as coronary artery bypass grafting [3] and mitral valve repair[4] to be effectively performed. However, the lack of haptic feedback in current robot-aided minimally invasive surgery systems is still one of the major downsides of such systems.Manuscript