UN Sustainable Development Goals Addressed
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Goal 9: Industry Innovation & Infrastructure
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Goal 12: Responsible Production & Consumption
2021 Global Design Challenge Finalist
This design concept was developed by participants in the Institute’s Global Design Challenge. The descriptions below are from the team’s competition entry materials.
Location: Netherlands
Team members: Jinglun Li, Mathias Baumann, Eléonore Wild, Vadim Steveniers
Innovation Details
This bio-inspired seaweed dryer was inspired by the camel’s nose, which has an amazing dehumidifying system, the Hercules beetle, which has a body composed of a micro-scale 3D chitin network that enables water absorption, and the moth’s eye nanostructure formation that is efficient at collecting light. These combined strategies create a dry and hot air flow that passively reduces seaweed water content, while preserving the active components, such as vitamins, lipids, and other bioactive molecules. The simple, user-friendly solution relies solely on bio-inspired passive mechanisms to warm-up and dehumidify the air intake. Therefore, it drastically reduces the energy consumption in the seaweed drying process, while delivering a high quality product with an extended shelf life.
Define the problem being solved.Seaweeds are a key resource for the food sector and many other industries such as pharmaceuticals and cosmetics. Seaweeds have a 80% water content upon harvest and thus need to be dried in the next 24 to 48 hours to prevent spoilage. The goal is to bring the water content below 10%, while preserving the active components, such as vitamins, lipids, or other bioactive molecules. This drying step usually requires complex logistics which consume a lot of energy. Hence, the challenge the team aims to solve is to dry seaweeds in a simpler, more energy-efficient way, while maintaining a high product quality.
What organisms/natural systems helped inform this design?The camel nose is an amazing dehumidifying system: its hygroscopic cavity has a spiral shape which creates a high surface area. This increases the water condensation rate on its internal surfaces, collecting water at every breath. The Hercules beetle is another insect whose body is composed of a micro-scale 3D chitin network, enabling water absorption. A color change occurs when the pores are saturated with ambient moisture. The moth eyes also caught the team’s attention, since they are composed of hemispheres extremely efficient at collecting light due to their nanostructure array. These strategies were identified to efficiently create a dry and hot air flow that passively reduces seaweed water content.
What does this design do?This design can be decomposed in two parts: The air treatment unit and the drying chamber. The air treatment unit is an array of hollow tubular structures connected to the drying chamber. These tubular structures (~2.5m long and ~15cm diameter) host various bio-inspired features that both dehumidify and heat the intake air flux up in the following sequence: water condensation, moisture absorption, and temperature increase. First, the ambient air undergoes a dehumidification process by condensation on a camel nose-like circumvoluted structure with high surface area. The moisture present in the air is further decreased with a dehumidification process by adsorption, going through a Hercules beetle-inspired microporous filter. It is then warmed up by solar radiation, thanks to a moth-eye inspired anti-reflective nano-coating. Finally, the air enters the drying chamber, an elevated cylindrical structure where freshly harvested seaweeds are laying on drying trays stacked on top of each other (~15cm intervals). The air enters at the bottom of the drying chamber and dries the seaweeds as it rises up, thanks to passive convection dynamics. The warm, and now humid, air exits the drying chamber at the top, creating a depression that will suck ambient air at the entrance of the air treatment unit.
How does this solution address the problem or opportunity?This solution relies solely on bio-inspired passive mechanisms to warm-up and dehumidify the air intake. Therefore, it drastically reduces the energy consumption in the seaweed drying process, while delivering a high quality product with an extended shelf life. Nonetheless, this technology is simple and user-friendly, which makes it accessible and facilitates its implementation close to seaweed harvesting locations. The drying treatment can directly be performed on-site to reduce the weight of biomass that needs be transported, resulting in less energy and CO2 emissions.
Element: How compatible is this design with all surrounding living systems? Is it safe? How is it more sustainable than the alternatives?This design is compatible with all kinds of terrains and climate conditions, making it highly versatile. The modularity of this design enables the user to easily combine multiple units without requiring any alteration of the environment. Unlike traditional driers that rely on large fans and heaters, the system relies on renewable and freely available energy (air and sun). As it only exhausts warm humid air and readily available distilled water, there are no harmful by-products generated. Also, the entire operation system is carbon neutral, and conducive to life. In addition to this, the various components are low tech, optimizing structure at the smallest scale to increase the efficiency of the system. The low tech elements are therefore long lasting and easy to maintain.
(Re)connect Element: Describe how this innovation helped the team connect with the natural world.All members of the team have scientific backgrounds and are biomimicry specialists. In this project, the team had an extensive bio-brainstorming phase. Looking into the nature-inspired lessons in all scales, the team landed on a few champion organisms. One of the biggest findings in the process is that the answers to humidity management and sunlight harvesting are hidden in the species that lives in tropical or subtropical arid ecoregions. When humans are building energy consuming fans and heaters to dry materials, the species we are learning from are well-adapted to desert environments by simply using convoluted or porous structures to extract water from air. These humbling lessons have inspired the mechanisms of the design. By developing this design, the team became more conscious of how to, not only make use of what nature provides, but become participants of the nature around all of us.
How were Nature’s Unifying Patterns or Life’s Principles applied to this design?The passive operating process ensures that the system does not consume any additional energy than what it needs. To optimize its drying efficiency, the team made sure the form of the product fits with the function: three levels of structural elements that extracts humidity from air and a chamber that aids air circulation. This design allows the drying chamber to function in most weather conditions and climate regions, hence being locally attuned. Moreover, the unit can easily be combined with other units to propose a modular system builded from the bottom-up that follows nature’s principle. The team designed the first drying steps by proposing specific shapes or structures to optimize the most energy demanding steps of the drying process. This allows for the ability to critically reduce the energy required in the drying process. Finally, the shape allows the optimization of the process within a smaller design instead of maximizing its size.
