3D printing – a technology that can build a house and make food sustainably
- It is estimated that 150 million people are homeless worldwide. Habitat for Humanity estimated in 2015 that 1.6 billion people around the world live in “inadequate shelter”.
- Food is responsible for approximately 26% of global GHG emissions and 31% of total food emissions come from livestock and fisheries.
What is 3D printing?
- Also known as Additive Manufacturing.
- 3D printing is a process of making solid objects from a digital file. A digital model is turned into a physical three-dimensional object by adding one material layer at a time until the object is created.
- It is the opposite of subtractive manufacturing which involves cutting out/ hollowing out a piece of metal or plastic.
- It is possible to create complex shapes using less material than traditional manufacturing methods by 3D printing.
How does 3D printing works?
- It begins with a 3D model which is the blueprint of the physical object.
- The model is sliced by the slicing software into thin 2-dimensional layers and then turned into a set of instructions in the machine language (G-code) for the printer to execute.
- After the slicing is done different methods can be used depending on the requirement. The methods are mentioned later.
- It usually takes 4 – 18 hours to complete.
- Plastics are used as material mostly but metals can also be 3D printed.
Different methods of 3D printing:
- Material Extrusion (FDM): Material is selectively dispensed through a nozzle or orifice
- Vat Polymerization (SLA & DLP): Liquid photopolymer in a vat is selectively cured by UV light
- Powder Bed Fusion (SLS, DMLS & SLM): A high-energy source selectively fuses powder particles
- Material Jetting (MJ): Droplets of material are selectively deposited and cured
- Binder Jetting (BJ): Liquid bonding agent selectively binds regions of a powder bed
- Direct Energy Deposition (LENS, LBMD): A high-energy source fuses material as it is deposited
- Sheet Lamination (LOM, UAM): Sheets of material are bonded and formed layer-by-layer
Benefits and limitations of 3D printing:
- Geometric complexity at no extra cost: the additive nature of the technology makes it possible to create complex shapes at no extra costs.
- Very Low Start-up cost: it does not require any specialized tools and the cost only depends on the amount of material used, time taken, and post-processing if required.
- Customization of each and every part: Just by changing the digital 3D model, parts can be customized without affecting the cost.
- Low-cost prototyping with quick turnaround: Parts that are printed on a desktop printer are usually ready overnight and orders placed to a professional service with large industrial machined are ready for delivery in 2-5 days.
- Large Range of materials can be used: Plastics, metals, ceramic, wood, or carbon particles.
- Lower strength & anisotropic material properties: Since the objects are built layer-by-layer, they are weaker and more brittle in one direction by approximately 10% to 50%.
- Less cost at higher volumes
- Limited accuracy & tolerances: Parts required for critical use are finished with CNC machining to improve the tolerances and surface finish.
"3D printing offers great geometric flexibility and can produce custom parts and prototypes quickly and at a low-cost, but when large volumes, tight tolerances or demanding material properties are required traditional manufacturing technologies are often a better option."
Eco-friendly use of 3D printing:
- New Story and two Mexican construction companies are building a neighborhood of 3D-printed homes in Tabasco, Mexico. The homes are built using a 3D printer, the Vulcan II. The houses are created in pairs with each house taking around 24 hours of total print time to complete. A specially mixed concrete that hardens quickly is used and the machine prints the structure in a series of layers creating a ridge-effect in the walls. The houses are 500 sq feet having a living room, a kitchen, a bathroom, and two bedrooms. The project is one of several home-building programs led by New Story. So far, it has built more than 2,500 homes in Haiti, El Salvador, Bolivia, and Mexico. The Tabasco project is the first 3D-printed community.
- Aleph Farms scientists have grown lab-printed steaks. Cells were taken from a healthy, living cow and grown into a tissue supported by an edible scaffold. The cells are fed with no more than what they need to grow. It takes 3 weeks to produce a steak instead of 18 months. Almost no land and water are required. The lab conditions mean that there is no need for antibiotics either and scientists have fortified steaks with extra vitamins. Meat demand is expected to rise by 70% between 2006 and 2050. Globally, livestock accounts for 14.5% of GHGs emissions. It takes 16,400 L of water to produce one-kilo beef. Animal husbandry is the prime driver of deforestation. Slaughter-free steaks could help us to enjoy meat in a way that does not harm animals and earth.
- Other innovative uses of 3D printing:
- Touchable Pictures: Visually impaired people could see photographs. Pirate3D made a home printer “Buccaneer” that can print 3D version of a photograph which can be visualized via touch.
- It will soon be possible to create implants that fit our individual needs and differences. From bone implants to prosthetic limbs and devices used by dentists, we can print anything.
- 3D print shops could burgeon where customers will be able to order printed-out products. This is going to reduce the number of items being shipped around the world – cutting down the carbon footprint of e-commerce.
3D printing is in the very initial stage. This technology is going to revolutionize the manufacturing sector. With innovations taking place at an unprecedented rate in 3D printing we could hope that we will be able to reduce the waste and carbon emissions that come from industries. Also, 3D printed food would help to reduce the emissions that come from the agriculture and food sector besides providing highly nutritious food.
We need to spread awareness as very little people know about this technology.
In the future it would be possible to make almost anything using 3D printing.
We have to make sure that it gets the right kind of investment and promotion required so that innovations can take place to make it more efficient for larger volumes of goods.
We have very little time left to prevent the catastrophic changes in climate and remember the clock is ticking very fast….