Imec presented an optomechanical ultrasound sensor on a silicon photonic chip that has an unprecedented sensitivity due to an innovative optomechanical waveguide.    Because of this high-sensitivity waveguide, the 20-µm small sensor has a detection limit two orders of magnitudes better than piezoelectric elements of identical size.    The low detection limit of the sensor enables new clinical and biomedical applications of ultrasonic and photoacoustic imaging such as deep-tissue mammogra...