This article by circulatenews.org/ investigates the technological advances that are encoding intelligence into materials. According to the author, there is a change in the fundamental relationship between materials and information content in the objectives that we make. And this will have large implications for the circular economy into the future.
The recent Intelligent Assets report, launched by the Ellen MacArthur Foundation in January 2016, framed important questions on the rise of Internet of Things (IoT) and its intersection with the circular economy. New networked devices are unlocking information on the location, condition, and availability of assets. Tracking and tracing devices, product passports, and sensor networks all generate data that can be used to create more efficient and effective resource flows. However, most of these technologies assume that physical material itself, for example plastic pellets, is fundamentally ‘dumb’ and therefore has to be managed with external systems that record information such as composition, quantity, and supply chain history.
An emerging host of scientific and manufacturing techniques are challenging this assumption by unlocking material intelligence through an intricate dance involving material, structure, and form. New techniques allow us to digitally program the rules of molecular assembly of materials and the properties they exhibit at larger scales. This is changing the fundamental relationship between materials and information content in the objects we make, and it has large implications for the circular economy.
The key to making sense of these new manipulations of the physical world is to recognise that we are using digital information to control the physical world at new levels of scale and precision. As an information science, materials become subject to a new set of computational techniques, where materials are treated as a set of micro-scale building blocks that can be digitally manipulated2. Examples from the biological world make this easier to visualise. DNA is assembled from a set of repeatable building blocks, as are proteins. These building blocks are physical units of information that help program life’s many forms. One can also see this idea in the way the structure of a butterfly wing reflects particular wavelengths of light to create colour, or the shape a protein folds into in order to perform a specific function in the body. The key insight here is that material form – its shape and pattern and hierarchical structure – is embodied information. In a way, it is a physical program that helps direct the organism’s function.
To see this in action, we can explore cutting edge examples of encoding information in materials, starting from the molecular scale, and working our way up to the scale our naked eye can see. At the very small scale, researchers are using this principle of building form to function by creating materials that self-assemble based on shape. Mimicking the specific ways proteins are designed to fold, scientists are programming matter to behave like Lego blocks, where the rules of assembly are encoded into the structure of the blocks themselves3. To understand the importance of this, we can use an example of a child building a Lego house. Even if he or she finds it difficult to place the bricks perfectly on top of one another, it doesn’t affect the overall integrity of the building because the design of the bricks limits how they stack on top of one another. Put another way, the Lego brick is designed to detect and correct the errors of the child4. Molecules can be pre-programmed to assemble into materials using the same logic. This is what Neil Gershenfeld describes as the digitisation of materials. Gershenfeld compares digital materials to digital computing, where converting a message to a string of 1s and 0s allows the computer to detect and correct errors in a signal or process5. In the future, manufacturing machines may be able to do the same, treating raw materials like strings of digital data.
Other scientific advances are scaling up the molecular level to a smart substance the eye can see. This is captured in the idea of ‘fitting form to function’, one of ‘Life’s Principles’ that guides the science of Biomimicry6. Fitting form to function uses the principle of creating structure across linear scales. Put simply, this means creating patterns in a material that impact how the material behaves at different sizes, or length-scales7 . For example, designing in honeycomb structures at the micrometre or centimetre scale can create a material that is strong and light, good at absorbing energy, and has important thermal and acoustic properties8. Another example comes from researchers at Harvard University who have recently 3D printed a composite material that mimics balsa wood. They state the importance of this work as follows: “The most ubiquitous cellular composite is wood, which not only supports substantial self-weight and wind loading, but efficiently transports nutrients over long distances to sustain growth. By controlling composition and architecture over multiple length scales, natural materials are able to achieve remarkable properties from biological polymers, e.g. cellulose and lignins”9 . Although we might treat wood as a typical raw material, this reveals that it has been intricately designed as a high performance product. To achieve such performance characteristics, the researchers 3D printed a cellular wood-like structure using ink embedded with nanoparticles designed to align in a certain direction, just like the fibres in balsawood. Even though the naked eye may not penetrate its secrets, there is information designed in at nano and micro scales that contributes to the overall characteristics of the material.
At the MIT Media Lab, researchers are introducing a new design paradigm, one that takes its cue from materials. As Neri Oxman notes, “in nature, shape is cheaper than material, yet material is cheap because it is effectively shaped and efficiently structured”10 . This elegance in design comes from flipping the standard workflow of product design on its head11. As Oxman notes, designers commonly start from a form they envision, select the structures needed to create that form, and finally choose the materials that fit the requirements of structure and form. Nature builds in the opposite direction. Available materials are gathered and inform the structures that can be added. These structures help shape the final form that the object takes. Outside forces, such as temperature, stresses and strains, shape each design step. This results in the final object being highly adapted in form and function to its environment.
This means that a single material can be designed to be more or less dense, or have different patterns at the micro level so as respond differently to stresses and strains. This is how human bones are built, for example, with areas that are more or less porous based on where they must bear load. It is also the way a palm tree grows. If you take a cross section of a palm tree you can see that the trunk gradually decreases in density from the core to the outer bark. This allows the palm to grow to great heights without collapsing under its own weight. Researchers have mimicked this by 3D printing variable density concrete12 for building structures.
Although this is a simple concept, traditional manufacturing techniques cannot cope with such a design brief. Oxman and her research group have solved this challenge through a technique called Variable Property Design (VPD) that uses a computer model to first simulate and then 3D print the material voxel by voxel (think pixel by pixel) so the printer can vary the material pattern continuously. In this approach, “material precedes shape”, and “it is the structuring of material properties as a function of performance that anticipates their form”. This is referred to as a type of material-based design computation13. The fact that this novel technique is nature-inspired and uses 3D printing is no accident. 3D printing is a digital fabrication technology that mimics the way nature builds, adding material layer by layer. Unlike subtractive techniques, were a block of material is cut down to a specific form, layer-by-layer fabrication allows the fine-tuning of form and structure.
As a final example of the power of encoding information into materials, we can look at how objects can be designed to respond to an outside force so that it changes over time. 4D printing14 is a technique for creating an object that responds to a change in its environment in a pre-programmed way; for example, when an object is printed with a hydrophilic material layer, it responds to the presence of water by changing shape. This is a step towards living materials15, designed to change in response to their environment.
How do these innovations relate to the circular economy? First, if manufacturing evolves to harness water-based chemistry, it may allow the use of many more biocompatible and biodegradable materials. When layered with sophisticated structural patterns, waterbased materials such as hydrogels may be designed for new and elegant applications16, unlocking the door to high performance fabrication with ubiquitous bio-friendly materials at local levels of scale. It may become possible to envision a future where high performance products are made from easily accessible, natural materials that can be fed into biological cycles as easily as leaf litter.
Second, if we design intelligent materials that use structure to attain high performance properties, using bulk metals and toxic chemistry may cease to be preferred engineering options. Nature challenges us to see information everywhere: in the fold of every wing, in the structure of every blade of grass. If we design materials this way, the distinction between biological and technical nutrients may become blurred. Elements such as iron and magnesium, although framed as technical nutrients for the circular economy, are also part of biological processes. Iron helps transport oxygen in the body, while magnesium is crucial for photosynthesis. A rule of thumb for materials in the circular economy may be less about intrinsic properties, and more about access to and concentration of nutrients.
Third, unlike today’s economy in which recycling is akin to unscrambling an omelet, materials that can be programmed to assemble like Lego can also be programmed to disassemble. With digital information for disassembly encoded in the very materials that make up products, waste flows will become data flows – the very definition of intelligent assets.
Reflecting back on what this means for the circular economy model, a provocative question arises: can we think about information and materials as separate flows? As digital manufacturing emerges as the new norm, will that even be possible? A fundamental rethink may be in order, and may uncover hidden economic potential in treating materials like information flows, unlocking new sources of value. Such a rethink may bring us closer to how natural systems manage materials: as molecules of data.
To read the original article, visit http://circulatenews.org/2016/05/raw-intelligence-what-digital-materials-mean-for-the-circular-economy/.