The rolling moss that gathers no stones — BBC The Green Planet & Biomimicry
“Water plants create some of the most beautiful, bizarre and important habitats on earth. To hold on in torrents, plants use a kind of superglue. Some are armed with vicious weapons to fight titanic battles for space. Others form perfect spheres and escape from animal enemies by rolling. Where nutrients are washed away, plants turn into hunters of animals, laying traps and even counting to ensure their success. Brilliantly coloured flowers smother lakes, and in one magical river in Brazil, the water bubbles like champagne as plants create the atmosphere itself.” — Water Worlds — BBC The Green Planet
Where to watch — https://www.bbcearth.com/shows/the-green-planet
The latest science estimates that life evolved on earth between 3.77 and 4.28 billion years ago in reddish-brown (ferruginous or iron-rich) sedimentary rocks, probably formed around marine hydrothermal vents arising from weak points in the Earth’s crust. Exploring how life — and plants in particular — colonised and thrived in the water world is the topic of this episode of the series.
And what another excellent episode it was. We were immersed in the ecosystems of the Caño Cristales, Columbia, The Plantal, Brazil, frosty regions of Japan, rainforests of Venezuela, and coastal regions where we focused on the importance of seagrass to planetary health.
For those who like to explore the natural world, what came to mind was collaboration and competition as the battles for survival eked out in water bodies around the world. So is there potential for new types of adhesives, solar arrays, folding techniques, pumps, materials, manufacturing, carbon sequestration and ecological health taken by watching this series? Well…yes.
Plant Adhesives
Let’s start with some concepts that are early in the R&D phase. For example, you may have heard of mussel-inspired adhesives? But what of those taken by replicating the chemical properties to those found in stems of the Macarenia clavigera? Research by The University of Utah, is developing protein-based adhesives inspired by how plants, such as Macarenia clavigera adhere to surfaces under extreme forces found in fast-flowing water.
Nature has developed a whole portfolio of adhesives produced by animals such as mussels with a holdfast and algae such as kelps, both of which can resist storm forces in the sea.. In particular, researchers have been looking into plant-based adhesives for their useful properties of biodegradability, resource-efficiency, and renewability, making them a better and more environmentally friendly alternative to current petroleum-based adhesive materials.
Aquatic organisms, both freshwater and marine, have evolved many ways to stick things together underwater. These bioadhesives are produced in a watery state, yet form a strong glue. They are adaptations that have evolved to fulfill specific roles in the organism’s lifestyle. Bioadhesives can provide permanent or temporary attachments, depending on the organism’s needs.
Biomimetic engineering should not consider natural glues as optimal solutions for underwater adhesion. Organisms live under numerous constraints, and adhesion is a multivariate optimisation process. There would be no evolutionary pressure to improve one function, like adhesive tenacity, to well beyond limitations imposed by factors like availability and capacity to utilise resources.
Organisms have limited pre-adapted building blocks to work with and face severe material processing restrictions imposed by narrow physiological conditions and the difficulties of regulated secretion. An example of potential appropriation of pre-adapted components into glue is the hypothesis that the curing mechanism of barnacle cement may be evolutionarily related to the biochemistry of blood clotting.
Underwater bioadhesives are not particularly strong. For example, byssal thread and plaque assemblies created by mussels had tensile bond strengths of 0.2–0.3 MPa. Therefore, mimetic adhesives for human technology must achieve higher underwater bond strengths.
Natural underwater adhesives offer more tricks to be learned. Individual mussel foot proteins interact in vitro, revealing how they fit together like puzzle pieces. Synthetic analogues may eventually adopt a hierarchical structure.
Bulrush
Buckling is a significant failure mode for long and slender columns subjected to axial compression. This type of failure mode should be avoided in structural design so that the load-carrying capacity of materials can be fully utilized. Traditionally, columns or rods are optimized in geometrical shapes, such as drum-shaped rods that can take a higher buckling load than uniform cylinders. Because the materials towards the centre of the rod axis provide less bending resistance, hollow rods will have higher buckling resistance than solid rods with the same amount of material. The hollow stem (culm) of bamboo resists buckling with internal plates that keep the section of the stem circular and stop it from collapsing.
The exceptional buckling resistance of the Bulrush plant’s roots, stems and other structures inspired a group of researchers to build a biomimetic rod generative model optimised by machine learning. The generated structures not only exhibit 150% better buckling resistance than their natural counterparts, but they are also 3D printable, which provide considerable potential in additive manufacturing for design and building of bridges. It’s not so simple, however, since ‘scaling effects’ mean that changing the absolute size of a structure commonly changes the forces within the structure. Which is why pigs will never be able to fly.
Wetland Ecosystems
The vibrant wetland ecosystem shown in the documentary has been the inspiration for many technological innovations. One exciting example is provided by the European Space Agency, who were inspired by the regenerative ecosystem. The MELiSSA Project aims to create a circular life-supporting system that recycles organic waste and carbon dioxide and generates water, oxygen, and food in space. Functional Ecology is one way to describe this.
The main components of the systems include:
- Waste compartment bioreactor;
- Nitrification bioreactor that recycles urine;
- Photo-bioreactor that produces oxygen;
- Plant chamber unit.
Early testing of prototypes, both terrestrial and in space, shows that this project still requires more flight experiments and improvement to validate the ambitious vision. Following this thread, other projects inspired by ecosystem interactions include a wastewater treatment technology applying biodiverse ecosystems, Turenscape’s ecological landscape architecture, eco-remediation company Biomatrix.
Carnivorous Waterwheel Plant
Programmes like this tend to make us think of other innovations that have not been featured. One of these is the sibling to the project mentioned in the previous article, Flectofin. Flectofold is another ‘plant-inspired kinetic architectural structure’. Again, there is a collaboration between the University of Stuttgart, ITKE, and the University of Freiburg, Plant Biomechanics Group.
Inspired by the hinge-less motion of an underwater snap trap, Aldrovanda vesiculosa (a carnivorous plant), Flectofold was developed. Based on computational simulations from its biological role model’s elastic and reversible actions, which can be identified through computation; this actuation principle is abstracted into a simple curved line folding geometry with particular flexible hinges that form when pressure is applied at specific points along their length during construction — making them perfect for generating large amounts quickly without having to worry about increased weight due to other materials used in traditional frameworks like heavy-duty metal plastic.
The purpose of the facade developments from this research cluster, Biological Design and Integrative Structures, is to explore more sustainable architectural and construction solutions. Check out more of their work.
Lotus plant
Although the lotus’ self-cleaning ability was possibly known in Asia long before (the Bhagavad Gita references the lotus effect), its mechanism was only discovered in the early 1970s, after the advent of the scanning electron microscope.
The lotus effect is a term for self-cleaning properties that result from ultra-hydrophobicity, as demonstrated by the leaves of Nelumbo, the lotus. The surface of the leaf has a multiscale micro-and nanoscopic structure of waxes, which reduces the adhesion of dirt, so that droplets of water can easily wash the surface clean. Most plants, such as Tropaeolum (nasturtium), Opuntiana (prickly pear), Alchemilla, cane, and the wings of some insects, also have ultrahydrophobicity and self-cleaning properties. Look for droplets on the surface of the leaves after a heavy dew or rain. Lotus effect is everywhere.
STO, a German building supply company, has turned this into a successful product with their StoColor Lotusan® paint. Lotusan facade paints and renders have the unique Lotus-Effect and excellent physical properties. The Lotus-Effect ensures that beautiful facades remain attractive for longer. In addition, it enhances the self-cleaning effect: dirt runs off with the rain. Regularly, the facade is kept clean and dry.. In addition, algae and fungus attacks are prevented indefinitely. Other companies that have developed similar innovations are Evonik, BASF, and GE.
Giant Amazon Water Lily
The fascinating world explored of floodplains in the Amazon highlighted the battle to make the most of the water and access to sunlight. We witnessed the pioneer species of water lettuce, water hyacinth, and the mosaic plant compete to make the most of available resources. However, it was the Giant Amazon Water Lily, Victoria Amazonica, that really exploded onto our screens. Able to grow at up to 200 mm a day, the leaves of this plant takes over the space as they expand to capture as much of the available sunlight as possible
The design firm, Exploration, explored the Giant Amazon Water Lily during their exhibition, Designing with Nature. This allowed them to develop lightweight 3D printed tables. These beautiful tables used nature-inspired SKO software — a computer programme based on the adaptive growth patterns of trees and bones. The tables demonstrate the potential that 3D printing offers in achieving radical increases in resource efficiency by producing complex shapes with ease.
Finally, what about the rolling moss that gathers no stones? Marimo (also known as a Cladophora ball, moss ball, or lake ball) is a unique growth form of Aegagropila linnaei (which is not a moss but a filamentous green alga) found in a few lakes and rivers in Japan and Northern Europe. Under certain conditions, the algal threads clump into a green ball that can roll when pushed by the flow of the surrounding water. Normal photosynthesis produces gas bubbles, some of which are trapped in the Marimo, giving it some buoyancy. Since photosynthesis requires light, the balls tend to float clear of the bottom during the day and sink to the bottom at night.
This of course means that light can be used to actuate the marimo — shine a light at the marimo and it rises in the water; turn the light off and it sinks . . . slowly. It’s a simple machine. Researchers at the University of the West of England have used this effect to make actuators, biosensors and processors (oscillators and logic gates).. You can buy Marimo for your desk. Unlike your pet stone, it needs care and attention, but can live for decades and won’t need to be taken for a walk. It just goes on rolling.
Nature-inspired innovation is an idea that has been around for centuries. Still, it’s only recently started to make waves in the design industry. It borrows principles from nature and applies them to human-made systems. One of the most exciting things about nature-inspired innovation is its potential applications in new technologies — something we’re seeing more of every day! What other technologies can you think of? Leave your comments below.
By Richard James MacCowan, Yuning Chen and Julian Vincent.
Biomimicry Innovation Lab is a #foresight and biofuturist innovation consultancy that actively works in next-generation agriculture, manufacturing and urban solutions worldwide. Have a look at our latest research on ‘The State of Nature-inspired Innovation in the UK’ in collaboration with the angel and venture capitalists, the Nadathur Group.
We are exploring a range of projects relating to ecosystem services, planetary health and direct air carbon capture (DACC) with projects in South Africa, Madagascar and India utilising our evolving model, Project FIN.
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