The University of Pisa, Italy, has purchased a CERES microscale Additive Manufacturing machine from micro-scale AM provider Exaddon AG, a Cytosurge AG spin-off company operating as an independent business since 2019.
Acquired through the framework of the Center for Instrument Sharing University of Pisa (CISUP), the CERES machine will be utilised by Professor Giuseppe Barillaro, Associate Professor at the Information Engineering Department at the University of Pisa, and his team to further their research on the unique capabilities of microscale metal Additive Manufacturing.
Prof Barillaro explains that the CERES machine “will be exploited to carry out frontier research on advanced micro and nano materials and structures with application in electronics and photonics, biomedics and medicine, life-sciences and nuclear physics.”
Among this vast range of disciplines, cell transfection using nanoneedles is said to be just one area of research which Prof Barillaro cited as a target use for the CERES machine, referring to a 2016 study published in Applied Materials and Interfaces. The study aimed to show how cell membranes had different responses when brought into contact with arrays of different shaped micropillars.
In the study, the team used electrochemical micromachining, specifically lithography and acid etching to create silicon pillar arrays. When the cells contacted these pillars, the cell walls were permeated, whilst the cells remained viable, thus allowing certain molecules to be trafficked into the cells. This process, known as biomolecular trafficking, is said to be extremely relevant in modern biotechnology. Through changing the diameter and height of the pillars, the team were able to influence how this process occurred.
They found that different parameters of the pillars (diameter, spacing, etc.) informed different cell responses. This study demonstrates an ideal use case for the CERES machine; creating arrays of microscale pillars, but this time, out of pure metal; impossible with processes like lithography and etching.
As a test scenario, Exaddon R&D engineers additively manufactured 1 x 1 mm arrays of micropillars to test uniformity and repeatability of AM objects. The results can be seen above, and the translation to the cell transaction use case is readily apparent.
The pillar diameters of the silicon arrays in the 2016 study were either 500 nm or 1000 nm, depending on the array. As a comparison to this, the CERES machine can reportedly additively manufacture 1000 nm diameter pillars with a standard AM tip, and pillars with as little as ~250 nm diameter with a custom tip. Furthermore, these pillars can be additively manufactured in gold or copper, and on a variety of substrates, including gold, copper, and flexible polymers such as PEDOT.
According to Prof Barillaro, the CERES machine marks an important point for the use of microscale metal AM in biological research applications. Additionally, the wide range of research fields in which CISUP intends to use the CERES machine is expected to provide an excellent test of its versatility and applicability in fundamental research; from electronics and photonics, to biomedics and medicine, life-sciences and nuclear physics.
To mark the occasion, the Exaddon team created a scale replica of the famed Leaning Tower of Pisa, additively manufactured in pure copper with their CERES machine and at just 360 µm in height.