Dear Oliver,

I just scarfed down tuna with a side of kibble. That’s how I get the energy I need to investigate your questions.

To do that, I talked with Ming Luo. He’s a robotics scientist at Washington State University.

He told me that robots don’t eat like we do.

“A human has a digestive system,” Luo said. “That’s how food can be converted to energy. But a robot can’t do that. The robot can just take in energy directly.”

When you eat, your digestive system breaks down food into sugars, fats and proteins. They’re full of energy. Your cells use oxygen from breathing to release that energy. Then, you can use it.

A robot needs energy, too. But it doesn’t have organs to break down food or cells to turn it into energy. It doesn’t breathe in oxygen either.

Instead, a robot taps into a source of energy directly. It might get electricity by being plugged into an outlet to charge. It could use a battery that stores electricity. A very large robot might have a system that uses fuel and pressure to inject the robot with energy. That’s called hydraulic power.

So, why do some robots have mouths if they don’t eat or breathe? Many robots designed to interact with people have faces. That’s because people feel more comfortable when robots look a little human.

“For human-robot interactions, it’s better to develop something that looks like the human face,” Luo said. “Many people are afraid of robots. We must figure out the best way for robots to look and behave, so people feel less anxiety.”

It’s a challenge because a robot that looks too human also freaks people out.

That’s especially important for scientists designing robot caregivers. These robots could live with elderly people. They could help them take medicine or care for their pets.

Luo builds soft robots that are safe for people to touch—like this one that looks like an elephant’s trunk.


Have you heard of artificial intelligence or AI? It’s different from a robot. A robot is a machine designed to do physical tasks—like your body does. AI is a system designed to make decisions or learn—like your brain does. Some robots have AI built in.

I asked an AI chatbot what food it would like to try. An AI chatbot is a program that can have conversations with people.

“I don’t experience interest in the same way humans do,” ChatGPT said. “However, I find human food fascinating from a knowledge and information perspective.”

It told me some of the most interesting foods are spices, chocolate, tomatoes, potatoes, sushi and pasta.

Maybe someday we’ll invent chocolate-flavored electricity for our robot and AI friends.


Dr. Universe