3D printing technique uses ultrasound to produce complex composites
Tue 19 Jan 2016
A research team has designed a new style of 3D printing which is able to print combined materials using ultrasonic waves.
The engineers, based at the University of Bristol, demonstrated the novel method in which ultrasound is used to position millions of microscopic glass fibres into a tiny reinforcement framework. The layer is then placed using a focused laser beam, which cures the epoxy resin and prints the object.
The study explains how the researchers mounted a switchable, focused laser module onto the carriage of a conventional 3D printer, above the new ultrasonic alignment equipment. “We have demonstrated that our ultrasonic system can be added cheaply to an off-the-shelf 3D printer, which then turns it into a composite printer,” said Tom Llewellyn-Jones, PhD student in advanced composites and lead developer.
In the test, a print speed of 20mm/s was achieved – comparable to the speed of a standard 3D printer. The engineers showed the ability to build a plane of fibres into a reinforcement framework, and precisely orientate the fibres by switching the ultrasonic standing wave pattern during the printing process.
This technique, the team argues, allows for the creation of almost any type, size or shape of fibre, including complex fibrous architectures, such as those required in high-performing products (tennis rackets, golf clubs, aerospace components, and fishing rods etc.)
“Our work has shown the first example of 3D printing with real-time control over the distribution of an internal microstructure and it demonstrates the potential to produce rapid prototypes with complex microstructural arrangements,” said Bruce Drinkwater, a professor of ultrasonics in the university’s Department of Mechanical Engineering. “Orientation control gives us the ability to produce printed parts with tailored material properties, all without compromising the printing.”
Dr Richard Trask, a researcher in multifunctional materials in the Department of Aerospace Engineering, added: “As well as offering reinforcement and improved strength, our method will be useful for a range of smart materials applications, such as printing resin-filled capsules for self-healing materials or piezoelectric particles for energy harvesting.”
The teams paper, 3D printed components with ultrasonically arranged microscale structure [PDF], was published this week in the journal Smart Materials and Structures. While lead researcher Llewellyn-Jones does not predict the new technique to be adopted at large scale in the near future, he believes the method could be an important addition in 3D printing companies following further testing and development.
