Scientists Create Knitting Machines to Make Solid Wood Furniture

Yuichi Hirose has a unique dream: to create a machine that can knit furniture.

Imagine a machine that not only knits fabric, but can also create sturdy objects like chairs and tables from yarn.

If you get bored with your couch, you can simply rip it apart and make yourself a new ottoman.

Hirose, a doctoral student in robotics at Carnegie Mellon University (CMU), calls this technique “solid knitting.”

After more than a decade of work, Hirose, working with a research team led by Associate Professor James McCann, has turned this dream into reality.

“My dream is to make these sturdy knitting machines available everywhere in the world,” Hirose said.

Hirose was inspired by a software project by McCann that made it easy to reprogram commercial knitting machines. The software allowed for the creation of custom 3D knits, although they were hollow shapes that could be stuffed rather than solid objects. The two began working together to enable uniform knitting.

By 2020, Hirose had built a prototype of his knitting machine, but the COVID-19 pandemic delayed further work. In 2022, Hirose joined the CMU Textiles Lab and the robotics doctoral program. The team presented their solid knitting research and the machine prototype at SIGGRAPH 2024, an annual conference on computer graphics, where he received an honorable mention.

The prototype machine, about the size of a clothes dryer, is currently limited in the shapes and sizes it can make. It can create triangular or rectangular prisms of varying lengths. The machine uses elastic string as yarn, resulting in surprisingly strong knitted objects. “It looks a bit like a pile of felt or the sole of a shoe,” McCann said.

Although the current machine is limited, the technique could also be used to hand-knit larger and more complex shapes, such as a pair of sandals. Hirose plans to take future research in two directions: building a larger machine for furniture production and creating a smaller machine for precision objects.

“We hope other people will build their own robust knitting machines and come up with ideas that we haven’t explored yet,” McCann said.

The research team also included Angelica Bonilla Fominaya, who created artwork using the technique, and Mark Gillespie, who developed 3D visualization software to aid in the design process. More information can be found on the project website, including instructions and videos on how to hand-knit the solid objects.

Solid knitting is similar to 3D printing. Much like 3D printers build objects layer by layer, solid knitting builds shapes by adding knit fabric layer by layer. Instead of using glue or melted plastic, each new layer is sewn onto the previous one.

Hirose came up with the idea in 2012 while studying digital manufacturing at Keio University in Japan. Inspired by a Claytronics project that involved modular robots that could create different shapes, Hirose sought a more durable and reconfigurable solution. This led to his concept of solid knitting.

After completing his master’s degree and working for a few years, Hirose secured grants, quit his job, and began building a solid knitting machine in 2018. Using rows of snap-lock needles, similar to those in commercial knitting machines, his machine manipulates yarn to create solid objects.

Hirose’s vision of knitting solid furniture may soon become a reality, bringing a new level of versatility and creativity to home furnishings.