Explainer: What Is 4-D Printing?

Additive manufacturing – or 3-D printing – is 30 years old this year. Today, it’s found not just in industry but in households, as the price of 3-D printers has fallen below US$1,000. Knowing you can print almost anything, not just marks on paper, opens up unlimited opportunities for us to manufacture toys, household appliances and tools in our living rooms.

But there’s more that can be done with 3-D printed materials to make them more flexible and more useful: structures that can transform in a pre-programmed way in response to a stimulus. Recently given the popular science name of “4-D printing”, perhaps a better way to think about it is that the object transforms over time.

These sorts of structural deformations are not new – researchers have already demonstrated “memory” and “smart material” properties. One of the most popular technologies is known as shape memory alloy, where a change of temperature triggers a shape change. Other successful approaches use electroactive polymers, pressurised fluids or gasses, chemical stimulus and even in response to light. … (Read more)

Source: TheePochTimes.com