Looks like the link I gave is bad. Try looking at the Wikipedia entry, particularly the "Aerial Robots" section.

I'm afraid I'm going to have to disagree. I think that we don't do enough biomimetic design, especially for production systems. Look around you. What was built using biological principles? The answer's probably "not much".

The problem seems to be engineers' blindness to "solved problems". Once somebody comes up with a workable solution, everybody just iterates upon it rather than stopping and rethinking the problem entirely. Take the "bat-craft" example. UAV design has consistently been a process of taking classic aircraft design, and then shrinking it. The problems are well understood, but you're never going to get any revolutionary features.

A couple of years ago, I was part of a competition for AUV design (autonomous submarines). Every single entry, except for ours, used the same principles that we've been using on submarines for forever. Pressure hull, with tandem thrusters for turning and propulsion. We tried to go with a more "natural" design, copying fish (flooded hull, the whole body was a control surface).

Talking to the big defense contractors that build these things for the military, all of their designs lacked any biomimetic features. Current AUV design consists of taking classic submarine designs, making them smaller, and whacking out the crew compartment. A lot of them are pretty cool, but they're certainly not borrowing anything from nature.

The same situation exists with UAV design. Look at the designs for the Int'l Aerial Robotics Competition. These are the engineering students that get recruited to design and build "the real thing" for Northrup Grumman and General Atomics. Smart guys, but they're (generally) not looking to nature.