Small-batch winemakers and academic researchers are always seeking new methods to further their understanding of the winemaking and yeast fermentation process. Important advances include improvements in testing equipment, as well as improved processes, including automation and robotics. In order to produce insights relevant to at-scale manufacturing, researchers must be able to simulate the kinetics of volume production in small batches. Traditionally, water-filled airlocks integrated with testing flasks have been the ‘go to' solution for small-batch fermentation research that can mirror the conditions of volume production. The airlocks keep oxygen away from yeast during the fermentation process while allowing carbon dioxide to escape. This helps simulate large tank kinetics in a small-batch process.
Professor Vladimir Jiranek and Dr. Tommaso Watson, leading academic researchers at the University of Adelaide, had the vision to automate their research processes by integrating robotic sampling of key lab components—in this case, the water-filled airlock, the design of which had not changed in decades. This case study describes the airlock redesign challenges faced by this research group, their journey through various manufacturing alternatives, and their ultimate solution based on a redesign and production with Carbon’s technology. Working with a leading contract manufacturer, The Technology House (TTH), the research team successfully produced a redesigned airlock using Carbon’s M Series printers and high temperature resistant CE 220 resin.
The first challenge Dr. Watson and the team tackled was to improve the efficiency of the research process by introducing robotic sampling of flasks used for testing. A robotic arm would be used to draw samples from these flasks, reducing the number of manual steps in the testing process and therefore the potential for human error. Previously, a technician had to sample the flasks manually to study the fermentation kinetics. The second challenge was to change the airlock design so that a large number of flasks could fit on a static test platform. This meant that the airlock needed a complete redesign.
Figure 1 shows a traditional water-filled airlock and shake flask used by the team prior to the redesign. The purpose of this airlock is threefold:
- Allow CO₂ produced during fermentation to escape
- Maintain anaerobic conditions by preventing oxygen in the air from entering the flasks
- Prevent microbial contamination from the outside environment
PRODUCT DEVELOPMENT JOURNEY
From the outset, Dr. Watson and the team worked on reducing the form factor of the airlock and flasks so that they would be able to fit more flasks on the test platform, thereby enabling robotic overhead sampling. When the team embarked on the redesign, they were targeting to fit 96 flasks on the test platform. Prior to reaching the final solution based on Carbon’s technology, the team explored two other manufacturing approaches; each of which required an entire product development cycle.
In the first approach, the airlock was designed and manufactured from several stainless steel parts assembled with silver soldering.
- Compact design to support robotic sampling
- Robust construction
- Sterilizable by autoclave at 121°C
- Silver soldering can corrode due to the acidic environment during the fermentation process and by the CO₂ produced
- Heavy stainless steel can damage the glass flasks
- Lack of internal visibility for water level observation
- Expensive to produce
- Difficult to manufacture due to multiple parts
COST OF DEVELOPMENT: High, due to machining of individual steel parts and soldering
TIME FROM DESIGN TO PRODUCTION: Long, due to machining and soldering complexity
In the second development approach, the research team tried to address the disadvantages of Approach 1 by using a different material. Due to the complex design, the team explored the design freedom offered by additive manufacturing and used two commonly available thermoplastics, ABS and PLA, to 3D print the airlocks using a layer-by-layer deposition technology. Using this approach, the team also hoped to address the high weight disadvantage, as well as the lack of internal visibility of the airlock.
- Lightweight and does not damage the glass flasks
- Easy to prototype
- Compact design
- Refinement of design enabling complex internal airflow chambers
- See-through for water level observation
- Resistant to corrosion
- Traditional layer-by-layer process materials (ABS or PLA) are temperature sensitive and are not autoclavable at 121°C
- Adhesion imperfections between deposition layers reduce functionality, for example water leaks
COST OF DEVELOPMENT: Very high, due to new technology learning curve
TIME FROM DESIGN TO PRODUCTION: Very long, due to challenges associated with airlock design iteration such as printing air channels, overhanging surfaces, and solving adhesion imperfections
In the third and final approach to product development, the research team looked for a solution that combined both the flexibility and design freedom of additive manufacturing with autoclavability and required functionality. The team was introduced to Digital Light Synthesis™ technology by The Technology House (TTH), a leading contract manufacturer. With their wealth of experience in using Carbon’s technology and the M Series printers, the engineers at TTH evaluated the research team’s design, materials, and functional requirements, and began production using Carbon’s Cyanate Ester resin (CE 220)—delivering the perfect airlock.
ADVANTAGES (in addition to those listed in Approach 2):
- Superior finish, compared to layer-based additive manufacturing methods
- Isotropic and homogenous part
- Mechanical characteristics combine to deliver the perfect seal against water and CO₂
- Carbon’s CE 220 meets autoclavability requirement at 121°C
COST OF DEVELOPMENT: Low, due to ease of air channel printability with Carbon technology
TIME FROM DESIGN TO PRODUCTION: Short, less than one week
Academic researchers at the University of Adelaide, led by Professor Jiranek and Dr. Watson, were looking to solve a process challenge by replacing an error-prone manual process with the robotic sampling of flasks. To achieve this, they had to innovate on the airlock design. Using Carbon’s technology, researchers produced the most robust functional parts at the lowest cost and in the shortest development time. Table 1 shows the comparison of all three product development approaches, as tracked by Professor Jiranek and Dr. Watson.
Table 1: Comparison of cost and time for the three product development approaches
The final airlock is more compact and replaces the previously bulky flasks with smaller flasks (Figure 5). This miniaturization also unlocks the ability to accommodate 384 flasks instead of the initial target of 96 flasks, enabling easy robotic sampling. The University of Adelaide with TTH’s continued partnership plans to produce and use thousands of these CE 220 airlocks over the next few years. This new airlock design represents an important new contribution to small-batch winemakers and research teams worldwide, as they further their understanding of wine research.
Additive manufacturing unlocks design freedom for engineers, industrial designers, and researchers alike, allowing them to completely rethink traditional designs, materials, and processes available at their disposal to make final parts. The research team at the University of Adelaide innovated on an airlock design that had not changed for decades and had become a bottleneck for their wine research process efficiency. The team innovated on the part design, the material used, and the manufacturing process used to make the final part. They not only achieved a better functioning part that helped them move to robotic sampling but also produced airlocks with over 60% lower cost of development and over 67% lower time of development, compared to both alternative approaches (Table 1).
The effectiveness of Carbon’s manufacturing solution will appeal to both engineering leaders and business leaders alike, as organizations across industry verticals embark on their product development cycles. Carbon’s technology offers engineering grade resins and robust industrial printers with great software capabilities to help teams rethink product design and ultimately move into final production. Carbon enables a true digital manufacturing solution with shorter product development cycles, where engineers iterate on product designs rapidly, and business leaders can launch to market differentiated products faster.
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