This work addresses the microrheology of soft and biological materials such as poly(ethylene)oxide solutions, type I collagen gels and endothelial cells using a novel oscillating optical tweezers technique.This advantageous technique is based on grabbing probe particles suspended in the media of interest with a tightly focused laser beam, measuring displacements and phase shifts of the particles motion from which to calculate the viscoelastic properties of homogeneous and inhomogeneous materials as the function of frequency and time. The validation of the optical tweezers microrheology is...