Bier, a former national representative unicyclist, said it gave students something to look forward to and made memorable demonstrations of mathematical and scientific principles.
"Certain classes and topics lend themselves to different kinds of tricks," Bier said.
"If it's something such as rotational inertia I'll pull out my diablo, which is like a giant yo-yo that spins around, and I'll do a bunch of tricks and talk about the physics of what's going on.
"And if I'm talking about projectile motion, instead of thinking about firing a bullet, I'll throw juggling balls around the room and we can talk about the physics of a juggling ball as it goes up and down."
He said surveys showed students appreciated watching the entertainment as it helped them to focus in the second half of lectures.
"Your students enjoy it a lot more if you're passionate about your subject area. And if you bring some of your personality in, they enjoy it even more," Bier said.
"I enjoyed working as an engineer and a mathematician but I also love circus and related stuff. It's fun to bring those two together."