Robotic stingray powered by light-activated muscle cells

Really amazing work. It's also a handy demonstration simultaneously of how far we've come in biomimesis and how far we have to go.

Many disciplines and a ton of research and expertise came together to create something that mechanically reproduces the locomotion of one of the simpler animals. Think of how much it took to do this, and how many orders of magnitude more complex (and in how many ways) simulating or recreating the nervous, circulatory, and other systems would be.

It's exciting that we've done so much, but IMO it's even more exciting that it provides some perspective on how much more there is to discover and build in this area.