Targeting bio-sensing applications of ZnO in BioMEMS, thin films ZnO were grown by dc magnetron sputtering under different deposition parameters and their morphological and mechanical properties were analyzed using AFM, XRD, XTEM, and nanoindentation techniques. The films have nano structured granular surface suitable for bio material binding while their roughness remain very low even at about 1 mu m thickness. The XRD studies showed the highly textured formation of films with c axis perpendicular to surface and a 'bulk' columnar structure has been seen by XTEM. Nanomechanical characterization of ZnO/Si(100) structures in darkness and under a relatively weak UV irradiation revealed a possible application of the coating on cantilever sensors using photoplasticity as a post-deposition stress and deflection control mechanism. The reversible photoplastic effect on films with thickness between 55 and 1012 nm caused by UV light exposure has shown an increase of the hardness of up to 25%. In addition the ZnO layer induced stress on the surface was estimated using CoventorWare simulation program. Preliminary results are shown that control of structural and surface properties of ZnO thin films via growth conditions may make dc magnetron sputtered films ideal coatings for micro cantilever sensors.