Technology Forward

How to explode design freedom

Thanks to additive manufacturing, a design tool takes on greater importance. That tool is the lattice structure.

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. For design engineers, though, lattices used in additive manufacturing can deliver specific mechanical properties to an object, often in the form of a stiffness-tomass ratio.

Lattices can sometimes be thought of as kind of a meta-material – an architected material – where you have material properties that are different from an original material, such as a polymer, that you might have used in a design. For some users, the use of lattices is exploding their design freedom.

One basic advantage of lattices is that you can achieve mechanical properties not easily achievable with foams, in addition to having a lattice function like foam in many designs. But you can also use lattices in areas totally different than those you might use with foam. One example is COVID-19 nasal swabs, which used a lattice design to obtain enough material for testing.

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 additive manufacturing. Attempting to make these intricate geometric shapes using injection molding and machining is often cost prohibitive.

Today, though, 3D printing easily creates lattice structures. One of the more recent examples is the latest athletic shoe from Adidas. But lattices have been used in helmets, saddles, shoes, nasal swabs, robot grippers, and in other designs. Lattices are even being studied for use in understanding how pulmonary airways work.

Programs that help you design with lattice structures are trending this year. One reason is that there are thousands of useful geometric shapes suitable for lattices. But it can be a challenge determining which structure is right for a project. Some of the newer programs offer guidance in selecting the right shape for a design.

And, lattices function well in conjunction with topology optimization or generative design programs. This combination helps designers consider different material properties for different points of the design.

Thus, consider lattices as an alternative to obtaining some mechanical properties, as they could be a way to use one material and still get that variation of material properties you need in a design.

The beauty of additive and lattices is that you can specify the mechanical properties you need with minimal material usage and minimal cost.

The wider use of lattices in your design can be one more tool in your toolbox. DW

Leslie Langnau llangnau@wtwhmedia.com

On Twitter @ DW_3Dprinting