Abstract—In this paper, we present the design, fabrication, and testing of a new micromachined fiber optic sensor probe to conduct oblique incidence diffuse reflectance spectrometry (OIDRS) for in vivo estimation of optical properties of human skins. The probe consists of three source fibers, two lineararray of collection fibers, and four micromachined positioning devices for accurate align- ment of the fibers. Micromachining plays a significant role in the probe development by enabling device miniaturization, low-cost fabrication, and precise assembly. The new probe has been suc- cessfully used to estimate the absorption and scattering coefficient spectra of skin with an optical spectrum between 455 and 765 nm.