Poly(dimethylsiloxane) (PDMS) has been considered for the first time for defining cantilever-based microoptoelectromechanical systems (MOEMS) by ways of soft lithography. The systems shown have a high degree of integration, comprising cantilever-waveguides, lenses, self alignment systems and seismic mass. The very low Young's modulus allows defining thick PDMS-MOEMS for mechanical sensors with sensitivities similar to its nanometer scale silicon counterparts. Experimental resonant frequencies of the proposed MOEMS are in agreement with the numerical simulations done, with Q factors in agreement with the PDMS properties. Finally, when a 1.58 mg droplet of ethanol is dispensed on the cantilever, there is a bending of the cantilever, causing an increase of the relative losses until 25 dB, returning to its initial value when the droplet evaporates.