In Zhao's eyes, it's like modern toys consisting of plastic or wooden bricks and other components for children to build things with. "Though demanding, building with the stalks makes me feel like I am playing sometimes," he says.

According to Zhao, all the articles are composed of numerous mortise and tenon joints that fit together.

To ensure the best quality materials, Zhao plants his own sorghum on over 400 square meters of land in a village near his home.

"The sorghum I grow is a hybrid I discovered from my research, which yields thin but harder stalks that are perfect for me to work with," Zhao says.

Zhao is pretty proud of the quality of his stalks. "The sorghum stalk has a particularly hard skin. It's very durable and stable after it has been dried and treated," he says.