Imagine buying a piece of flatpack furniture that can assemble itself. Or purchasing a dress online that takes shape in front of your eyes in your living room.
The 3D printer already allows users to print simple objects at home, but scientists are now working on 4D printing, using "smart" materials that can change shape by themselves.
Currently, 3D printers use a nozzle to deposit material in layers to build up a small inanimate object, usually made from a single material such as plastic.
However, researchers are now combining different types of plastics and fibres to create "smart" materials that change shape when they come into contact with stimuli such as heat or water.
Objects designed in this way can expand, fold or unfurl into pre-designed forms after being printed, in a process dubbed 4D printing.
Skylar Tibbits, from the Massachusetts Institute of Technology, is pioneering the research with Stratasys, the digital manufacturing company.
He said: "We asked if we could print things that change shape and change properties to behave in precise programmed ways. We call it 4D because it adds time, rather than printing static objects. Smart materials are materials where you subject them to some kind of energy and they change shape or appearance."
Brigitte Nerlich, a science professor at the University of Nottingham, said that current methods of 3D printing were already becoming "old-hat, commonplace and perfectible".
Now, by weaving in water-sensitive materials at key points, a straight plastic strand could be 4D-printed to fold into a cube when wet.
Car tyres could be printed to improve their grip in the rain, while flat sheets of metal or plastic could be printed to fold themselves into pre-designed shapes when unpacked, which could be used to print self-assembling furniture.
Jesse Louis-Rosenberg, from Nervous System design studio, said he hoped to use 4D printing to create a dress that could be printed in compact form then unfolded. Using a scan of the customer's body, the dress could be designed to fit perfectly and would be created with a series of tessellating segments.
A computer model would then compress the design into the smallest possible space to fit inside a normal 3D printer. The customer would simply download the design, print it and unfurl it.
"I would describe 4D printing as printing something in one configuration that self-assembles into another," Mr Louis-Rosenberg explained.
"The way we're doing it is to design a shape as a foldable fabric and digitally fold it into a smaller size for printing which can then unfold," he said.
Since first sharing his research last year, Mr Tibbits has been approached by a range of companies, including sportswear firms who want to print shoes that can adjust their own support or ventilation depending on conditions.
He said that other uses could include water pipes being printed to expand or contract with flow and even a device to mimic the human intestine.
The US Army has given a grant of $855,000 to fund research at the Universities of Harvard, Illinois and Pittsburgh.
By Kaya Burgess
With thanks to The Australian
