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Bubbles and Structures: Improving our economy’s resource performance

There’s been a flurry of new material science innovations associated with improving our economy's resource performance.  Many of these innovations are what I consider low-hanging fruit.   For example, a recent article in Fast Company describes an MIT-developed technology for reducing the mass of plastics by adding tiny gas bubbles.  The article raises potential problems with focusing purely on minimizing mass (including the need to ensure a design’s quality), and we'll discuss those in a future blog.  But let's talk about innovations in light-weighting plastics and how they relate to the underlying concepts of dMASS.   First, note that there’s a key relationship between form and mass.  When you get the form right - that is to say when you get closer to understanding how nature arranges itself  – you are more able to eliminate mass without compromising the value or desired functionality of a product. 

For the first time in decades, automakers are actively pursuing ways to reduce the mass of cars to improve fuel efficiency without compromising safety.  In fact, Ford has identified vehicle weight reduction as a major part of its plans to improve fuel efficiency. 

Mass savings can occur without a functional reduction in material performance for a number of reasons.  Most notably, but not surprisingly, many components of cars and other goods are simply overdesigned - way overdesigned - and improved understanding of how different materials perform under different circumstances allows for better matching of materials to needs.  Maintaining performance must also occur because of the way that the nitrogen atoms comfortably disperse themselves among the other organic carbon chain structures.  They are usurping a certain amount of the volume (space) within the product, which causes the polymer molecules to readjust their structural relationships.  Trapped gasses can obviously have structural characteristics.  The bubbles could allow the redistribution of compressive force around them similar to the way an arch allows for eliminating some of the mass of a wall or a bridge by efficiently redistributing the compressive force around it without weakening the structure.  (See our video, Design Matters, for more on how this works.)  For engineers and material scientists, the trick is finding the right arrangement of open spaces and structural elements that best perform a desired function.  

There are many other examples of bubbles (or empty space) being used to displace mass.  Small bubbles are being used in structural building materials like cellular concrete and a variety of foam products.  They are also beginning to appear in building and construction products as insulating material for both sound and heat, as in super lightweight insulation.  IKEA is using a technology that creates strong structural components in lightweight furniture by replacing the normally solid inner portion with a honeycomb arrangement of cardboard that has large open spaces.  The result is furniture that’s as strong as wood, yet has a mostly empty core.  It’s achieved by finding the most effective way to arrange the cardboard network inside.  In A Simple Lesson in Sustainability and Creating Business Value, Kristin mentioned a software applet that instructs printers to arrange tiny holes in the ink surface of printed letters, saving 25 percent of ink without noticeable affect for the reader.  A Dutch company called Freedom of Creation has several interesting designs, from iPhone cases to furniture, that reduce mass by using empty spaces.  

In most cases, this kind of mass reduction can be achieved because of an increased understanding and mimicry of structural arrangements in nature.  In the end it is form that determines the behavior, and therefore the value, of a given material or product. And mass can be reduced by better matching certain forms with certain tasks.  This is the beauty and direction of real design innovation.  For products where maintaining material volume is an important benefit, integrating space and structural elements is an important strategy for achieving dMass objectives.

MuCell, the lightweight “bubble” technology for plastics, is a great example of a strategy to improve mass performance.  The technology introduces nitrogen gas bubbles into plastic during injection molding.  The largely-empty gas bubbles are distributed among the otherwise regular molecular structures, reducing the total amount of plastic mass required to make automobile components or other products.  According to the company licensed to use it, the technology results in material that’s strong but weighs up to 50 percent less than comparable material.  Ford estimates it could reduce vehicle weight by 10 percent.  As we have seen with many examples in our newsletter, mass savings accrue not only through the reduction in material of the product itself, but in the multiplier effect of resource savings throughout the product life cycle - it takes less fuel, water, and capital to mine, manufacture, and transport fewer materials.

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