Biological systems have evolved many material designs for various mechanical purposes with additional properties such as lightweight, transparency, photoreception, and flexibility. In this talk, I will discuss my research on biological and bio-inspired multifunctional structural materials. In particular, the advantages of utilizing high-resolution synchrotron x-ray tomography techniques for this study are highlighted. First, we investigate the structural basis for the highly transparent yet damage tolerant bioceramic material from the windowpane oyster Placuna placenta. Combining quantitative indentation and synchrotron tomographic measurement, I show that the shell’s 3D integrated laminate structure leads to its remarkable damage resistance. Secondly, we explore the dual-functional design of the biomineralized armor of the chiton Acanthopleura granulata, which incorporates an integrated sensory system based on hundreds of mineral lenses. We demonstrated that these microscopic, mineralized lenses are able to form images, correlating well with ray-trace simulations by incorporating the quantitative structural information obtained from tomography data.