Before the Gutenberg press, the mechanical loom, the steam engine, or the computer became ubiquitous, there was a pause. The inventors had hatched the next big thing, and they wondered what would happen next. We’re living through a similar time—before 3-D printing goes mainstream and anyone can make anything, anywhere.
The ability to print out an object layer by layer on a machine the size of a microwave is about to democratize the making of things. Already, designers, architects, and engineers are using 3-D printers to prototype everything from hearing aids to hybrid cars. Makers are printing their own jewelry, guitars, even guns at downtown tech hubs where printers can be rented by the hour. If this trend goes the way of the personal computer, you won’t need a professional printing service. Your very own “iMake” will be whirring in your den.
If this sounds like the distant future, consider the Form 1 desktop 3-D printer now selling for $3,299, less than half the $7,000 starting price for Apple’s first color printer. Some DIY printer kits are as low as $400. Instead of printing 2D color photos, you’ll be printing 3-D objects designed by your favorite artisan. At first the printing will be slow and the color choice limited. Soon, speeds will increase, mixed materials will be available, and you’ll be able to print complex objects like cellphones on the spot. Retail is also set to shift. Your local auto parts store won’t need to warehouse thousands of parts; they’ll have five printers by the cash registers using powdered metals to create your order. Auto parts won’t crisscross the world; designs will.
The good news is 3-D printing creates far less waste because it forms objects to shape without molds or cutting. (That’s also why it’s called additive manufacturing, the inverse of current subtractive, cut-down-a-bulk-material approach). Its local nature promises to drastically reduce shipping and bring manufacturing back to neighborhoods. The worrying news is that 3-D printing could accelerate consumerism of throw-away plastics that are no more sustainable than what we buy now. And there’s the largely unexplored topic of toxins in the 3-D printing supply chain. Some polymer resins that fill the cartridges of 3-D printers come with their own warning labels—to avoid contact with eyes or wash clothes when exposed to them. While our neighborhoods may cheer about the new jobs at micro-factories, our workers may encounter new hazards. Even our kids may have to suit up to take out the hazardous waste trash.
We have to do better, and thankfully, we still have time. This is the moment to redesign manufacturing so that it leapfrogs the missteps of the first industrial revolution. At a minimum, the materials need to be common, safe, and recyclable from the start. Manufacturers need to be able to procure what’s known as the feedstock–the material you 3-D print with–locally, and then download a digital build file that imparts superior performance through structure. At the end of its life, the product must be “unzippable” so the feedstock can be fed back to the printer for reuse. And that’s where biomimicry—the mimicking of nature’s strategies and designs—has a great deal to offer.
A precedent for this kind of circular material flow exists in the natural world. Organisms create their artifacts—silk, bones, shells, feathers, etc.—with a bottom-up, built-to-shape manufacturing process. Source materials are common, abundant, and local. The chemistry is life-friendly, performed at low temperatures, low pressures, and without toxins or excessive waste. Thanks to a small pallet of feedstocks (only a handful of polymer classes make up most biomaterials), nature’s materials can be easily recycled.
To create performance, life adds structure or design to matter. For instance, a beetle’s shell is composed primarily of chitin, but it has functional attributes such as strength, breathability, waterproofing, and color—all created through structure such as laying up the chitin in a strong plywood-like hatch, adding porosity for airflow, nano bumps to shed water, or light-refracting layers to create color. Contrast this to our multiple functions/multiple materials approach. The seven layers of a potato chip bag can contain one material for waterproofing, a different material for excluding oxygen, a different material for inking, and so on, making it hard to recycle. The beetle uses only one material for multiple functions, but changes the structure as needed.
This simplicity stands in stark contrast to 3-D printing’s current path. In the last 25 years, the list of feedstocks has grown in number and toxicity (especially in the polymer segment), as have the energy requirements. Before this scenario is standard, we must design a small pallet of renewable, recyclable, waste-sourced feedstocks that compete in price and performance with conventional ones. Some current green entrants to the race, like starch-based polymers, will benefit greatly from new structural lay-ups to bolster performance. Following a circular economy approach, these materials should be sourced locally, manufactured benignly, and flow back to the printer rather than leaking to landfills.
I believe biomimicry will be vital to four key aspects of this vision: local sourcing, smart structure, safe chemistry, and reverse logistics. After 3.8 billion years of making majestic designs from simple materials, nature has much to teach us. Imagine sourcing our 3-D printer polymers from CO2 (as plants do) or waste carbohydrates (as animals do). For structure, imagine borrowing organisms’ highly evolved blueprints, just as Harvard’s Don Ingber did to create an aluminum-strong, insect-inspired plastic named “shrilk.” The chemistry inside the printer, if modeled on nature’s recipe book, could retire the “heat, beat, and treat” of old industrial processes. The same chemistries that build a product from the bottom up can be reversed to break it down, allowing materials to be reincarnated into new products, just as the nutrients in a log find their way into insects, then rodents, then hawks.
Taken to its full extent, this biologically inspired manufacturing system would signal a sea change in our materials economy. Hazardous manufacturing plants surrounded by razor wire and serviced by global shipping fleets would no longer be relevant. Communities could begin to meet their own needs, and ultimately control their own destiny just as organisms in prairies and oceans and forests do. When our manufacturing becomes as safe, circular, and planet-enhancing as theirs, we’ll be happy to welcome it home.