The second half of the 20th century has witnessed a productive interplay between chemistry and materials science—in fields as varied as polymers, catalysis, interface science, ceramics, and electronic materials. Society also has enjoyed the spectacular results-most notably in information and communications technologies—achieved by merging condensed matter physics and materials research. In contrast, connections between materials science and biology have been relatively weak. To be sure, materials research has made important contributions to medicine, but the discipline has yet to draw on biology in the same way that it has absorbed people, ideas, and skills from chemistry and physics. This is beginning to change. With increasing frequenc...