Enhancing Electromagnetic Coil Applications with 3D Printing

Ziv Cohen

Application Manager, Nano Dimension

Electromagnetic coils are one of those important electronic devices that are often taken for granted. Transformers and inductors are quiet components that make modern life possible, and they often don’t receive the attention they deserve. Given the importance of these devices, they aren’t going to be replaced anytime soon, and designers should explore new ways to incorporate these designs into new products.

3D printing for electromagnetic coil applications allows product designers to create new devices for purely electronic or electromechanical products with unique functionality and geometry. With Industry 4.0 in full swing, manufacturers and new product developers can greatly benefit from adapting additive manufacturing capabilities to these devices.

A 3D-printed electromagnetic coil.

Some Creative Electromagnetic Coil Applications

Many electromagnetic coil applications can benefit from 3D printing for fabrication. The performance of these 3D-printed coils rivals that of commercial off-the-shelf (COTS) components while giving designers significant freedom to create new products with novel geometry and form factor.

Flat Motors

One useful application of an electromagnetic coil on a planar substrate is as a driver in a flat, lightweight electric motor. Placing these coils on a flat substrate allows them to be incorporated into small UAVs that lack free space, children’s toys, and robots. In particular, new service robots for the disabled and elderly make copious use of flat motors due to the sleek exterior design of these robots.

Placing these coils on a planar substrate provides two advantages. First, the coils for these motors can be quite small, saving plenty of board space for other electronics to support the motor. Second, the torque provided by these motors can be tuned based on the size of the coil, the current it carries, and the driving PWM signal used to control speed. Working with an additive manufacturing system to develop coils allows these electrical performance aspects to be easily tuned, which eliminates the constraints imposed by COTS components.

3D printing provides a real advantage for printing coils in these applications compared to the use of COTS components. Many commercially available components are not tailored to the form and fit required in UAV and robotics applications. The complex packaging required in these applications limits the range of available motors for a given form factor. When the coils and PCBs for the electronics are additively manufactured, they can be easily adapted to the system’s packaging.

Copper coils for a motor.

Motor-less Electromechanical Systems

The magnetic field generated by an electromagnetic coil allows it to be used in a variety of applications that require driving of some mechanical element that cannot accommodate a motor. Some examples include miniaturized speakers or buzzers, electromechanical switches, or relays.

An additive process that 3D prints a coil directly on a substrate from nanoparticle conductive inks allows the coil to be designed with custom geometry as part of a planar or non-planar PCB. The ability to place an electromagnetic coil on a non-planar substrate is very useful, as some electromechanical systems have an odd shape. This allows the shape of the PCB to be adapted to the packaging, allowing for sleeker and smaller designs in finished products.

Embedded Inductors for RF Components

As one of the three fundamental passive electronic components, inductors appear in nearly every electronic device. An additive manufacturing system that is designed for PCB fabrication can be used to design inductors with custom geometry and print them directly on a substrate. The layer-by-layer printing process allows these inductors to be easily embedded inside the substrate if desired during fabrication, thus eliminating mandatory assembly steps in traditional fabrication and assembly with COTS components.

In mobile devices, printed inductors are very important as they are used as antennas for near-field communication (NFC). Currently, these inductors are printed on a phone’s main circuit board or on a separate board that connects with a flex ribbon. Using an additive manufacturing system to design these inductors for 5G-capable mobile devices allows designers to experiment with new geometries and embedding with the goal of reducing board space. The freedom over form factor and embedding with 3D-printed inductors also allow them to be used as antennas in passive NFC and high-frequency RFID tags.

RF antennas and amplifiers inevitably include inductors for impedance matching and filtration. In 5G-capable mobile devices, inductors are also used in antenna-tuning switches to allow a printed antenna to operate in multiple 5G bands. 3D printing allows designers to create inductors with a unique geometry that are embedded in a PCB for custom tuning switches, impedance matching networks, and RF filters.

Additively manufactured electromagnetic coils have applications in robotics.

Advantages of 3D Printing for Electromagnetic Coil Applications

During the prototyping phase, using additive manufacturing capabilities allows new designs to be produced and tested quickly thanks to the greatly reduced fabrication time offered by additive manufacturing systems. This expedites the successive design, build, and test iterations as the fabrication and assembly times with additive manufacturing are reduced from weeks to hours. Using an additive manufacturing system also allows a single product to be immediately produced and tested, which is very impractical with traditional manufacturing.

Other 3D printing processes for mechanical parts, such as fused deposition molding, can be complemented with an inkjet printing process for electronics. Using multiple additive processes for electromagnetic coil applications and their packaging allows high-complexity, low-volume products to be totally fabricated with comparable material costs, less fabrication time, and fewer assembly steps compared to traditional injection molding, casting, and PCB fabrication processes.

As more materials are adapted to 3D printing processes for electronics, as these processes become more sophisticated, and as new fabrication systems are developed, designers will only see their range of capabilities expand. Now is the time for electronics designers, engineers, and manufacturers to complement or replace their traditional fabrication capabilities with additive manufacturing systems.

Are you interested in implementing a unique geometry in your electromagnetic coil applications? If so, you need to use the DragonFly Pro additive manufacturing system from Nano Dimension. This system is uniquely adapted for 3D printing of electronics with unique shapes on planar and non-planar substrates. Read a case study or contact us today if you’re interested in learning more about the digital manufacturing DragonFly Pro system.

Ziv Cohen

Application Manager, Nano Dimension

Ziv Cohen has both an MBA and a bachelor’s degree in physics and engineering from Ben Gurion University, as well as more than 20 years of experience in increasingly responsible roles within R&D. In his latest position, he was part of Mantis Vision team—offering advanced 3D Content Capture and Sharing technologies for 3D platforms. The experience that he brings with him is extensive and varied in fields such as satellites, 3D, electronic engineering, and cellular communications. As our Application Manager, he’ll be ensuring the objectives of our customers and creating new technology to prototype and manufacture your PCBs.