This paper presents experimental results and analysis for different fiber optic microbend sensor configurations by varying the type of fiber, the inner section length of hetero-core fiber, mechanical periodicity, and the number of corrugations. This is the first hetero-core microbend sensor reported in the literature. Hetero-core fibers are built by inserting a single-mode fiber into two multimode fibers. Again as a first in the literature, a new hetero-core type of multimode-multimode-multimode configuration was introduced. It was shown that, this novel triple multimode hetero-core configuration is more sensitive than ordinary optical fiber and the multimode-single mode-multimode configuration. Experimental results show that, as the number of corrugations increases, the sensitivity of the sensor increases. It has also been shown that decreasing the periodicity and the inner section length of the hetero-core fiber also increases the sensor sensitivity.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.