Living Manufacture: Principles for a microbial 3D printer
Investigators: Martyn Dade-Robertson, Meng Zhang
Research Team: Thora H Arnardottir, Joshua Loh, Katie Gilmour, Sunbin Lee.
We envisage a bioreactor containing a co-culture of cellulose producing bacterium and bacterium which, in response to a light (optogenetic input), can selectively produce pigments, compounds, biocatalysts and/or non-catalytic proteins. These additions can modify the cellulose molecular structure and result in various material properties.
We propose first steps to develop a 3D printing process which involves the synthesis and modification of biopolymers from live microbes to make 3D functionally graded materials and objects. The project will integrate genetically engineered microbes and the design and building of a novel bioreactor as a part of a new type of 3D printer. The project will establish the principles of a new industrial fabrication system based on controlled biological production of biopolymers through growth. This new biofabrication system will have potential applications in a wide range of areas, including biomedical applications, complex composites for high-performance manufacturing and novel consumer products.
HARDWARE
Aim:
To create two prototypes: 1) a bioreactor which will be fed with a liquid culture containing BC producing bacteria and engineered optogenetic Escherichia coli which produces chromoproteins in response to light. 2) a bioreactor containing only BC producing bacterial cells with a change in the material properties will be achieved by dripping cellulose degrading enzyme onto the defined areas of the growing pellicle through a robotically controlled ‘print head to selectively weaken the cellulose structure.
We have developed a single modular system from a new design based on the liquid handling robot, ‘EvoBot’. This allowed us to build modules to drip different levels of chemical stimuli mounted on a rail system so they can be moved on the x and y planes. We have also built a module to monitor the height of the pellicle in real time.WETWARE
Aim:
Establish the optimum conditions and maximum growth of the BC pellicle with a novel BC fermenter design and nutrient supply strategy.
We have demonstrated a consistent growth of BC and a continuous (i.e. does not delaminate before or after drying) pellicle (d) by automatically feeding the nutrient and anchoring the initial pellicle growth at the liquid air interface to prevent movement of the pellicle layers. We have achieved +8 cm homogenous pellicles which we believe is unprecedented. This method is subject to a patent application.
Aim:
Ascertain the viability of the optogenetic method for altering the material properties in 3D.
By co-culturing K. xylinus with an optogenetic E. coli we were able to produce BC pellicles that were sensitive to light in 2D. We
demonstrated the application of our system to 3D pattern forming in hydrogel. This was achieved by exposing E. coli agar culture to a light mask. The masks where changed as subsequent new layers od agar were added. The resulting sections show that the pigmentation produced by the optogenetic E. coli is preserved in the agar. When dissecting the agar, distinct patterning of each layer was observed and lead to 3D patterns which have been further analysed to understand the resolution of the patterns.
SOFTWARE
Aim:
We developed a prototype software modelling tool which modelled patterns of diffusion through a growing BC given either optogenetic triggers (as patterns of light change on the surface) and diffusion of chemicals.
Publication and Dissemination Activities
Peer Reviewed Publications
Gilmour K, Aljannat M, Markwell C, James P, Scott J, Jiang Y, Torun H, Dade-Robertson M, Zhang M. Biofilm inspired fabrication of functional bacterial cellulose through ex-situ and in-situ approaches. Carbohydrate Polymers. (2022)
Presentations
“Biological Robots?” Robots that Build Symposium, Eindhoven. (2022)
“Living Manufacture: Principles for a microbial 3D printer”, 5th International Conference on Structures and Architecture (Aalborg) (2022)
“Biodigital fabrication of functionally variegated bacterial cellulose”, Synthetic Biology UK. (2021)
“Fibre Fusion, functionalized bacterial cellulose through BslA”, Synthetic Biology UK. (2022)
“Fibre Fusion, functionalized bacterial cellulose through BslA”, Living Textile Architectures, UK. (2022)
(Keynote) “Modelling Across Scales in Biological Fabrication“. Design Modelling Symposium, Berlin. (2022)
Exhibitions
Robots that Build - Dutch Design Week (Eindhoven) exhibited a video installation showing the working system. (2022)
BioFabricate (New York) Exhibited fabricator components and sample materials to an international audience of designers, industry representatives and academics. (2022)
Posters
Loh J, Arnardottir T, Dade-Robertson M, Zhang, M. Living Manufacture: A fabrication platform for producing functionally-graded bacterial cellulose, Synthetic Biology UK. (2021)
Loh J, Arnardottir T, Dade-Robertson M, Zhang, M. Living Manufacture: A fabrication platform for producing functionally-graded bacterial cellulose, Synthetic Biology UK. (2021)
Additional Activities
Design Sprint for Design for Planet Festival 2022 ‘Can we grow everything?’ Facilitated 2-day workshop with Masters students on future applications of our bio-fabrication technology.
The Living Manufacture Project is funded by the EPSRC Manufacturing the Future (Grant Number: EP/V050710/1).
