3D printing usually involves depositing molten plastic layers, laser melting metal powders, or using ultraviolet light to harden colloidal resins. However, a new technology has chosen another method, that is, using sound waves This technology was developed by a team of scientists from Concordia University in Canada. It is called direct sound printing (DSP).
In the current version of the technology, a transducer is used to send focused ultrasonic pulses, which then pass through both sides of a chamber and enter the liquid polydimethylsiloxane (PDMS) resin therein. Doing so will produce an ultrasonic field, which causes rapidly oscillating micro bubbles to temporarily form at a specific location of the resin.
As these bubbles oscillate, their internal temperature rises to about 15000 Kelvin and their internal pressure rises to more than 1000 bar. Although this sudden increase in temperature and pressure lasted only a few picoseconds, it caused the resin to solidify at the exact location of the bubble.
Therefore, by gradually moving the transducer along a predetermined path, it is possible to build a complex three-dimensional object -- one small pixel at a time. In addition to being able to produce very small, detailed objects, the DSP also allows non-invasive printing of structures within other structures with opaque surfaces.
With this technology, aircraft mechanics can imagine 3D printing maintenance on internal components without opening the aircraft fuselage. It is even possible to 3D print the implant in the patient without surgery.
In addition to PDMS resin, scientists have also successfully printed objects made of ceramic materials using DSP. They now plan to experiment with polymer metal composites, followed by pure metals.
Professor muthukumaran packirisamy, who led the study with Dr Mohsen Habibi and doctoral student shervin foroughi, said: "ultrasonic frequencies have been used for destructive procedures, such as laser ablation of tissues and tumors. We want to use them to create something."