A new method to realize arrays of micro-lenses using a sol gel glass replication technology is presented. Polydimethyl-siloxane (PDMS) master structures are used for the replication of thin glass membranes, which, by an appropriate annealing procedure, result in converging lenses with positive meniscus. Hereby, we exploit PDMS - sol gel surface interactions and thickness dependent changes in composition of the sol gel solution. The lenses are realized on a circular and square like basis. We characterize the micro-lenses by an optical imaging system and measure their focal length as a function of lens thickness and size. Also spherical aberration effects are measured.