A high sensitivity, batch fabricated, micromachined pressure sensor with interferometric readout is described. The transducer consists of a fiber V-groove, a 45 degree(s) stationary mirror and a silicon membrane, which are micromachined in two separate silicon wafers by anisotropic etching in KOH solution. The 45 degree(s) mirror provides a means of directing the light to and from the membrane with a horizontally mounted fiber, which is compatible with etched V-groove fiber alignment and positioning. A Fabry-Perot optical cavity is formed between the end of the fiber and the silicon membrane. The generated optical interference fringes are used to detect and measure the change in membrane deflection. The pressure range of operation and sensitivity are dictated by the thickness, size and material of the membrane and the wavelength of the light source. The sensor described here is designed for implantation in living bone tissue for the detection of necrosis. The ultimate, minimum size for this sensor is dictated by the diameter of one, single mode fiber, e.g. 125 microns.