Lattice structure in 3D printing

In automobile parts, medical implants, running shoes or hiking backpacks, we are seeing more and more products with checkered or honeycomb patterns.3D printed parts. You might think of these lattice structures (or truss structures as they’re called in English) as the latest innovation in 3D printing and design for additive manufacturing (DfAM). In fact, we are constantly surrounded by nature’s lattice structures. Think of bees’ nests, snowflakes, fences, sponges and even the Eiffel Tower.

A lattice or lattice structure consists of a network of nodes connected in patterns, called cells, that repeat or change to provide benefits in performance or part production. In traditional manufacturing, lattices are rarely visible because these processes cannot produce such complex designs. This is the advantage of additive manufacturing, which makes the mesh and3D printing is the perfect combination.

3D printed trellis (Image source: Sculpteo)

DiscussBefore 3D printing lattice structures, we first understand the types of lattices available. In principle, a network is formed by connecting nodes using line segments. Depending on the arrangement of line segments and nodes, regular or irregular patterns may appear. By modifying the density of the segments as well as the geometry and size of the elements, one can adjust properties such as the elasticity or rigidity of the part. There are many types of trellises and research is underway to develop more diverse and efficient trellises. However, the most common grids can be divided into several categories:

1、Planar lattice:These networks are based on two-dimensional planar structures which form three-dimensional parts. Since the layers are printed individually, they may need to be assembled later. This type of network includes tetrahedral patterns,Voronoi lattice and rhombus and hexagonal lattice (like honeycomb).

2、Pillar lattice:These networks are composed of connected segments that form a network by connecting nodes, corners or edges of cells. The printed layers overlap and fit together. The trellis may need to be reinforced with support material.

3、TPMS (Triperiodic Minimal Surface) network:These networks are based on trigonometric equations that determine the units. The basic shape of the trellis may vary.

There are many3D printed lattice structures are available. (Image source: Shenzhen JR Technology)

Grids can also be divided into periodic grids and random grids. Periodic arrays maintain a uniform pattern throughout the structure, while random arrays feature variations in cell shape, size, and arrangement to reinforce the structure in certain directions.

The choice of trellis depends on its final objective. The design takes into account the appropriate geometry and dimensions as well as the required rigidity. The buckling behavior, i.e. how the structure yields under pressure and in which direction, is also analyzed. Additionally, people often wonder if the mesh can absorb energy when deformed.

trellis design and3D printing

design3D printed lattices require specialized design tools. Although some modeling software provides basic functionality for networks, software specific to topology optimization or generative design is more reliable. Generative Design calculates the optimal design based on the required properties of the part and the selected printing method. If the project contains lattices, their cells, density and arrangement are also calculated.

Many tools are available for optimizationModels and creates 3D lattice structures, including Autodesk Within, nTop by nTopology, Meshify, 4D_Additive by Core Technologie, Netfabb or HyDesign by Hyperganic. The choice of design depends on the application, materials and printing technology.

With the help ofWith HyDesign from Hyperganic, you can design lattice structures. (Image: Hyperganic)

to useIt is much easier to produce lattice structures with 3D printing as they are often very complex and delicate. Additionally, printing lattices is faster than printing solid structures. In theory, a variety of materials and printing technologies can be used, but each process has its specificities:

1、existIn FDM and SLA printing, large lattice structures require support structures.

2、ForPowder processes such as SLS or MJF must provide sufficient access points to achieve efficient powder removal.

3、existIn DMLS, additional supports should be considered to avoid the 2mm limit of unsupported bridges.

These particularities are generally taken into account from the design stage.

The required properties of the parts and their applications are integrated into the design of the truss structure. (Image source:nTopology）

Challenges and Benefits of Scaffolding

The main challenges include cell orientation, distance between beams and angle to the printing platform. The grid must both meet the goals of the final piece and be achievable. Additionally, digital files for trellis designs can be very large (over1 GB), requiring significant computing power to carry out simulations.

However, its advantages are numerous:

1、Save material:The trellis could produce lighterspare parts, reducing costs and improving performance, particularly in the field of lightweight structures.

2、Improve quality:Mesh materials can improve shock absorption, increase flexibility or, conversely, stiffen the product to make it more durable.

3、Specific applications:The network increases the heat exchange surface area in heat exchangers and stimulates bone growth in medical implants.

Toucan Beak, a 3D printed heat exchanger with a lattice structure inside. (Image source: Aidro)

Applications of 3D printed lattice

Now let’s continue the discussionThere are certain application areas where 3D printed meshes show their potential. In the medical field, mesh is used not only in the aforementioned implants, but also in prosthetics and orthotics to optimize weight, strength or comfort.

Truss structures are particularly advantageous in applications where high performance and light weight are required, such as in the automotive, aerospace and aerospace industries. For example, usenToplattice and Shell&Lattice, Aerojet Rocketdyne was able to reduce the weight of the quad engine block by 67% and reduce production costs by 66%.

Use truss structures to reduce weightAerojet Rocketdyne engine block (Image source: nTopology)

But plaid is also becoming increasingly important and popular in the sports and consumer goods sectors. We see more and more3D printed protective gear and mesh padding. These meshes are found in bicycle saddles, helmet padding, protective clothing, etc., as well as in the midsoles of shoes. Especially with running shoes we want better energy transfer and higher performance.

This logic also applies to car seats or backpacks. For example, outdoor equipment expertsOechsler uses Magic tools from Materialize to improve the comfort of its innovative backpack featuring mesh construction. Furniture also began to adopt trellis, although in this case beauty seemed to take precedence over brightness.

These examples show that lattices already exist in many applications. withThis trend is not only expected to continue, but also to intensify in the future due to the advancement of the industrialization of 3D printing and the continued development of design possibilities.

Mesh structure for shock absorption and comfort (Image source:Oechsler)