Breeding better buildings

C ivil engineers are often very conservative in how they pursue their profession-and for good reason: If their designs don't work, things can fall down and kill people (as the recent bridge collapse in Minnesota so clearly demonstrates). Following novel approaches increases the probability of making such disastrous mistakes. It can therefore be prudent to build on designs that are known to function well. But global society is changing rapidly, and new challenges often call for engineers to innovate while simultaneously remaining vigilant about safety. Costs, competition, energy savings, climate change and security issues are several of the burgeoning concerns that new buildings must be designed to address. To create dramatically new kinds of structures, engineers can mine many different sources of inspiration, but the natural world offers perhaps the richest lode. Indeed, engineers have probably drawn ideas from nature for millennia: A fallen log may have inspired the first bridge; a cave entrance, the first archway. And as scientists gradually began to understand the mechanisms governing various biological processes, engineers of all stripes were able to apply this knowledge to building complex devices. (The most famous example of such "biornimicry" may be Velcro fasteners, the idea for which came from the observation of sticky burdock seeds.)