A piezoelectric microcantilever for sensing compounds or molecules. The piezoelectric microcantilever, may include at least one electrode, an insulation layer, a receptor, an immobilization layer, a non-piezoelectric layer and a piezoelectric layer. The sensor is capable of self actuation and detection. The piezoelectric layer may be constructed from a highly piezoelectric thin lead magnesium niobate-lead titanate film, a highly piezoelectric thin zirconate titanate film, a highly piezoelectric lead-free film. Methods of using the sensors and flow cells and arrays including the sensors are also described.