IEEE Spectrum had an article from a Chinese lab on “animal robots”. When I was back in grad school, we worked on a proposal for a similar project. We were going to connect moth antennae to a robot and use them as sensors to drive the robot around. Various people have worked on similar ideas over the years, and they’re a little disturbing but generally very informative.
This paper had a diametrically opposed approach. Instead of replacing the animal’s actuators with a robotic interface, they mounted a controller on the back of a rat and connected it to the rat’s motor neurons. Instead of creating a robot with biological sensors, they created a remote control animal.