A d d i t i v e
t e c h n o l o g y
Taking advantage of
lattice designs in 3D printing
Leslie Langnau • Senior Contributing Editor Lattice structures are those geometric shapes grouped together to create repeatable patterns for engineering purposes. The idea of lattices has been around for quite some time. You see these repeating patterns on buildings and bridges. For design engineers, lattices can deliver specific mechanical properties to an object, often in the form of a stiffness-to-mass ratio. Lattice structures have not been used as often as they could be because manufacturing methods that could produce them easily did not exist until the development of 3D printing / Additive Manufacturing. Injection molding and machining are often cost prohibitive when it comes to producing these shapes. Today, though, 3D printing easily creates lattice structures in helmets, saddles, shoes, nasal swabs, and in other designs. For example, lattices are being studied for use in soft robotics and in understanding how pulmonary airways work. The additive company Carbon offers a lattice design generator called Design Engine that automates the process of creating conformal, single-zone lattices. Using lattices in your design can “basically explode your design freedom significantly,” notes Hardik Kabaria, Director of Engineering at Carbon. Lattices can be made from metal or polymer materials. If you use the
38
September 2021
www.designworldonline.com
Carbon Design Engine, you’ll work with stereolithography and polymer materials. According to Kabaria, the Carbon Digital Light Synthesis system opened the door to more easily work with lattice structures. “The initial application we found and have had success with is in the area where, traditionally, you were using foam. So, if you're using foam for shoes, or helmets, or saddles, those are the places where you can replace the foam with polymeric lattice parts. “And the basic advantage there is you can achieve mechanical properties not easily achievable with foams. But we have also found some areas that are significantly different than foam replacements. And the example I would give is COVID-19 nasal swabs. “I've been working on a lattice-design computational-geometry algorithm that is dedicated towards these types of applications for quite some time. I would not have imagined that COVID-19 swabs are something that we would be able to make using lattice design ideas.
DESIGN WORLD
