Exone end to end binder jetting service

3D Printed Magnets In Functional Assemblies Could Lead to New Machines and Medical Devices

INTAMSYS industrial 3d printing

Share this Article

Since 3D printing began to diversify, allowing for the printing of materials beyond just metal and plastic, scientists have been experimenting with the 3D printing of magnets. 3D printed magnets can be made more quickly and less expensively than more conventional methods of production, and they can be easily made into complex geometries if so desired. While many researchers have 3D printed magnets, however, few actual use cases exist, but a new study entitled “3D Printing of Functional Assemblies with Integrated Polymer-Bonded Magnets Demonstrated with a Prototype of a Rotary Blood Pump,” applies 3D printed magnets to a rotary blood pump. Successfully 3D printing magnets embedded in 3D prints could open up the world to a whole host of new 3D printing applications. Tiny machines, medical devices, motors are just some of the things that could be possible. By letting a housing or another part of a device function as the case but also as a magnet the form factor and functionality of many devices could change radically.

To 3D print the pump, the ETH Zurich researchers created a filament made from thermoplastic combined with isotropic NdFeB powder. The material was used to 3D print a prototype of a turbodynamic pump with integrated magnets in the impeller and housing. The pump was 3D printed in one piece on a low-cost, consumer-level 3D printer (a Prusa i3 MK2 with a multi-material upgrade, to be exact), then the magnetic components were fully magnetized in a pulsed Bitter coil.

Besides heart transplantation, rotary blood pumps are the only option for patients suffering from end-stage heart failure. The pumps use magnets as critical components in the driving and bearing systems of the impeller. Unfortunately, currently available pumps have the side effects of hemolysis and thrombus formation, which manufacturers are attempting to address in the development of next-generation pumps. Regular 3D printing is being applied in the development of rotary blood pumps, but according to the researchers, to their knowledge, 3D printed magnets are not being used for testing new designs of medical devices.

“The basic design of the pump prototype is similar to that of conventional RBP designs—however, complicated geometries with inside twists and undercut elements would not allow for conventional manufacturing,” the researchers explain. “The bearing concept for the impeller consisted of two passive magnetic bearings for radial forces and a pivot tip for axial forces. For the radial magnetic bearings, hollow cylinder magnets were integrated into the impeller and housing. The impeller comprises of four blades with twisted internal blade channels in a helical shape around the inflow axis. In each of the blades, a driving magnet was embedded just above the bottom surface. The shape of the magnet was matched to the blade geometry, thereby maximizing the magnet volume. The impeller was actuated by magnetic coupling to a set of matching non-printed permanent magnets spinning on a servo motor just below the housing.

The pump was 3D printed on the first try, in a print that took about 15 hours. Arbitrarily-shaped magnets were integrated into the pump, and the magnetic filament, which the researchers called MagFil, was able to be printed from a standard spool without breaking. The hydraulic performance of the pump was then tested with water using an ultrasonic flow probe and pressure sensors at the pump inlet and outlet.

“An operation of the pump prototype at a maximum rotational speed of 1000 rpm, with a flow rate of 3 L/min against a pressure head of 6 mmHg was achieved,” the researchers state. “At higher rotational speeds, the magnetic coupling broke off and the delivered flow rate decreased concomitantly. The pump prototype could therefore not deliver a sufficient flow rate at head pressures that are realistic for clinically used RBPs.”

The researchers attributed this failure to inferior print quality caused by some difficulties with multi-material printing, but they still concluded that 3D printing is a promising method for speeding up the development process for medical devices and for creating devices with integrated magnets with geometrical complexity.

Authors of the paper include Kai von Petersdorff-Campen, Yannick Hausworth, Julia Carpenter, Andreas Hagmann, Stefan Boës, Marianne Schmid Daners, Dirk Penner and Mirko Meboldt.

Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.

 

Share this Article


Recent News

$51M to Ramp up 6K’s Production of Batteries and 3D Printing Metals

Secret Audit Reveals US Military’s 3D Printing Tech Vulnerable to Cyberattacks



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

3D Printing News Briefs, September 9, 2021: Events, Materials, & More

In today’s 3D Printing News Briefs, the first Formnext + PM South China finally opens this week. In materials news, a biomedical company introduced what it calls the first purified...

Featured

US Navy Issues $20M to Stratasys to Purchase Large-Format 3D Printers

The U.S. Navy has been steadily increasing its investment into practical 3D printer usage, as opposed to research. The latest comes in the form of a whopping $20 million contract...

3D Printing Webinar and Event Roundup: August 22, 2021

From food 3D printing and GE Additive’s Arcam EBM Spectra L 3D printer to 3D printing and CAD in a post-pandemic world and topology optimization, we’ve got a busy week...

Featured

The Largest 3D Printed Structure in North America: a Military Barracks in Texas

ICON’s latest 3D printed training barracks structure in Texas signals another positive step for the additive construction industry. Described by the company as the largest 3D printed structure in North...


Shop

View our broad assortment of in house and third party products.