Insights into Issues – 4D Printing
Understanding 3D printing:
3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file. The creation of a 3D printed object is achieved using additive processes. In an additive process an object is created by laying down successive layers of material until the object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object.
Working of 3D printing:
It all starts with making a virtual design of the object we want to create. This virtual design is for instance a CAD (Computer Aided Design) file. This CAD file is created using a 3D modeling application or with a 3D scanner (to copy an existing object). A 3D scanner can make a 3D digital copy of an object. Recently, companies like Microsoft and Google enabled their hardware to perform 3D scanning, for example Microsoft’s Kinect. In the near future digitising real objects into 3D models will become as easy as taking a picture. Future versions of smartphones will probably have integrated 3D scanners.
Application of 3d printing:
The worldwide 3D printing industry is expected to grow from $3.07B in revenue in 2013 to $12.8B by 2018, and exceed $21B in worldwide revenue by 2020. As it evolves, 3D printing technology is destined to transform almost every major industry and change the way we live, work, and play in the future.
- Medical industry
The outlook for medical use of 3D printing is evolving at an extremely rapid pace as specialists are beginning to utilize 3D printing in more advanced ways. Patients around the world are experiencing improved quality of care through 3D printed implants and prosthetics never before seen.
3D printing technology has been studied by biotech firms and academia for possible use in tissue engineering applications where organs and body parts are built using inkjet techniques. Layers of living cells are deposited onto a gel medium and slowly built up to form three dimensional structures. This is also known as bio printing
- Aerospace & aviation industries
The growth in utilisation of 3D printing in the aerospace and aviation industries can, for a large part, be derived from the developments in the metal additive manufacturing sector. NASA for instance prints combustion chamber liners using selective laser melting and in March 2015 the FAA cleared GE Aviation’s first 3D printed jet engine part to fly: a laser sintered housing for a compressor inlet temperature sensor.
- Automotive industry
Although the automotive industry was among the earliest adopters of 3D printing it has for decades relegated 3D printing technology to low volume prototyping applications. Nowadays the use of 3D printing in automotive is evolving from relatively simple concept models for fit and finish checks and design verification, to functional parts that are used in test vehicles, engines, and platforms. The expectations are that 3D printing in the automotive industry will generate a combined $1.1 billion dollars by 2019.
- It is predicted by some additive manufacturing advocates that this technological development will change the nature of commerce, because end users will be able to do much of their own manufacturing rather than engaging in trade to buy products from other people and corporations.
The revolutionary concept of 4D technology has a step by step processing; unlike 3D technology that is built on the piles of different layers on upon another, 4D is more like a transformation from one shape to another. Advances in the nano biotech world are being applied at a macro scale, using exciting new materials that can be programmed to change their form over time.
The fourth dimension in 4D printing refers to materials that are able to change and mutate over time when exposed to water, temperature changes and/or air to self assemble. 4D object formats will soon have APIs (Application Programming Interfaces) that enable designers to define the characteristics of the materials they are made from, which are then printed using sophisticated chemical calibrations to enable specific attributes and functionality.
4D Printing, developed as a collaboration between the Self-Assembly Lab, Stratasys and Autodesk, is a new process for printing customizable smart materials. 4D Printing entails multi-material prints utilizing the Stratasys Connex printer with the added capability of shape-transformation from one state to another, directly off the print-bed. This technique offers a streamlined path from idea to full functionality built directly into the materials, including; actuation, sensing and material logic.
Techniques of 4D Printing:
- At Harvard’s Wyss Institute for Biologically Inspired Engineering, a team of scientists is studying a way that a special ink, known as hydrogel ink, can change shape and form when stimulated with water. Hydrogel ink works by allowing the objects that it prints on to change shape to form new structures which are similar to those found in flowers. The tissue microstructures and compositions of different plants can change depending on the situation of their environments. Wyss has replicated the process by developing 4D-printed hydrogel composites which are programmed to contain precise swelling, allowing 3D-printed flowers to change shape when exposed to water and other environmental changes.
- At the University of Wollongong in Australia, Professor Marc Panhuis and a team of researchers have created the 1st 4d printed water valve that shuts when exposed to hot water and re-opens when hot temperatures subside by using a hydrogel ink that responds rapidly to heat. The team demonstrated the functioning of this water valve by pouring hot water through it and showing how it closed instantaneously and then re-opened when cooler water was pumped through it.
Application of 4D printing:
- We can use it to achieve robotics-like behavior without the reliance on complex electro-mechanical devices
- Home appliances and products that can adapt to heat or moisture to improve comfort or add functionality
- Childcare products that can react to humidity or temperature, for example, or clothes and footwear that optimise their form and function by reacting to changes in the environment
- There are also uses for pre-programmed self-deforming materials in healthcare – researchers are printing biocompatible components that can be implanted in the human body
- In the future we aim to produce larger structures which can handle more complex transformations, as well as smaller, miniaturised models which can be used in the body.
- 3d and 4d printing is set to revolutionize manufacturing the way we know it in the years to come