UNM scientists 3D print mechanical metamaterials for metered ink deposition

Electronic components can also be manufactured by roll-to-roll processes, where a special stamp transfers the printing material to the substrate. However, common defects, such us haloing or bridging, negatively affect the performance of printed materials for electronics applications. University of New Mexico researchers thus used a GT Professional nano 3D printer from Nanoscribe to create a 3D printed porous stamp.

To address this challenge, researchers around Michael Gallegos from Sandia National Laboratories and The University of New Mexico (US) worked on a new approach: 3D printed mechanical metamaterials for metered ink deposition. These porous stamps use capillary forces during mechanical deformation to enable metered material transfer. One of the main drawbacks in roll-to-roll processes is the excess amount of ink left on the substrate after lifting off the stamp creating the aforementioned defects. Therefore, the researchers aim at making the material dispense more controllable.

They used a Nanoscribe 3D printer – which implements 2PP technology – to fabricate stamps with micrometer-sized pores. In the stamping process, the pore-space acts as the reservoir and the mechanical deformation as the “metering pump”. When using a porous stamp, the suction force pulls the ink back into the stamp when lifting it off. This way, ink overspill can be avoided. Moreover, the researchers printed fibrous stamps to compare to solid stamps. They found that regardless of the density of fibers, fibrous stamps printed with greater fidelity as well as more uniform film thickness versus solid stamps. This work with regards to fluid mechanics opens up many applications for cost-effective, ubiquitous sensors.