Project Summary Rigorous biomechanical research relies on quasistatic, dynamic, and viscoelastic characterization. Although this is well accepted by the research community, experimental constraints, such as a need for minimal manipulation or a sustained in vivo environment, greatly limit the scope of biomechanical studies. Given the leading role of the University of California, Irvine (UCI) in biomechanics and mechanobiology, there is a significant need for innovative biomechanical testing instrumentation that will enable NIH-funded UCI researchers to probe many of the field’s unanswered questions beyond the capabilities of UCI’s existing equipment. In this proposal, we demonstrate the need for the purchase of a Polytec PSV-500-3D QTec Laser Scanning Vibrometer to support numerous NIH-funded research projects. The proposed Vibrometer’s ability to characterize the dynamic and viscoelastic properties of complex biological samples and biomaterials without damage is unparalleled. This proposal clearly delineates the major drawbacks of UCI’s current biomechanical testing equipment. In contrast to these instruments, the proposed Vibrometer’s advantages are extensive and include rapid contactless measurements, high resolution 3D scanning, multi-scale measurement capabilities, and portability, among others. These features are critical to maintaining highly demanding experimental conditions in complex studies, such as longitudinal characterization of cultured tissues or measurements concurrent with operating room procedures. There are no other instruments on campus or on the market that provide the proposed Vibrometer’s unique features. This proposal has been prepared by Drs. Kyriacos Athanasiou (PI), Jerry Hu, and Gabriela Espinosa in consultation with five other Major Users (Drs. Naomi Chesler, Anna Grosberg, Wendy Liu, Joshua Mauney, Ronke Olabisi) and three Minor Users (Drs. Zhongping Chen, Elliot Hui, Liangzhong Xiang). The initial set of Users represent numerous areas at the intersection of engineering and medicine, including mechanobiology, bio-microelectromechanical systems, tissue engineering and biomedical imaging. It is anticipated that interest in the proposed Vibrometer’s use will only increase, thus expanding its impact on current and future NIH-funded research at UCI.