A new device developed by researchers at the University of Berkley could prove key to the viability of bioprinting, an extension of 3D printing that might allow on-demand printing of frozen food, as well as living tissue, bone, and even whole organs, reports Futurity.
Layer-by-layer printing and assembly might give manufacturers the opportunity to explore different textures of food and enable them to develop food that is responsive to the needs of sick people. On top of that, the technology could also allow the development of industrial-scale manufacturing of frozen food, where the structure of ice crystals in the food is meticulously controlled at the single cell later throughout the product.
Although the concept of stacking thin layers to create a 3D object is not new to manufacturing, it is novel to do so with biological materials. The team has come up with a technique for preserving single cells, which freezes each 2D layer immediately after it is merged into the 3D structure. This process of freezing a single layer of cells provides optimal conditions for surviving the process of freezing, storage, and transportation.
“This is important because of the size of the ice crystals and the homogeneity of the ice crystals are a central element in the quality of the frozen food,” said Boris Rubinsky, professor of mechanical engineering from the University of California, Berkeley. “Right now, bioprinting is primarily used to create a small volume of tissue. The problem with 3D bioprinting is that it is a very slow process, so you can’t print anything big because the biological materials will deteriorate by the time you finish. One of our innovations is that we freeze the material as it is being printed so that the biological material is preserved, and we can control the freezing rate,” Rubinsky went on.
“There is a big difference between materials used in conventional lamination – like paper, plastics, ceramics, and metal – that are rigid, even in thin layers, and biological matter consisting mostly of liquid that is much less so,” commented Gideon Upkai, a graduate student in Rubinsky’s lab.
So, the team used hydrophilic and hydrophobic rigid surfaces onto which they print 2D layers. These specially designed layers allow them to transport the 2D layers across distances, regardless of the direction of gravity, for placement onto a 3D object. For future research, the researchers will work to better optimize this process, characterize the products, and determine the appropriate scenarios that present the most advantages.