3D printing technique breaks fresh ground in nano spheres
With most existing 3D printing techniques, the creation of overhanging structures is only possible with a trick: During the printing process, a template or mask serves as a placeholder and is removed afterwards. The process devised by ETH doctoral candidate Luca Hirt from the university’s biosensors and bioelectronics laboratory, the printing head does remove this obstacle, enabling future users to print even extremely complex structures without templates.
The technique at hand is based on the FluidFM system that has been developed at ETH a couple of years ago. The pivotal component of this system is a movable micro pipette coupled to a leaf spring. This part can be controlled very precisely. Today. FluidFM is applied in the first place in fields like medical and biological research.
Within his doctoral thesis, Hirt investigates the use of FluidFM in 3D printing, focusing on ways to deposit metals and other materials in solution on a conducting substrate plate by means of electrochemistry. Moving along the micropipette containing the material in solution in tiny steps, the scientists can “print” three-dimensional objects pixel by pixel. The size of the pixel depends on the size of the pipette orifice. The scientist can create pixels at sizes between 800 nanometres and 5 micrometres and combine them to form three-dimensional objects. In a first feasibility study, Hirt was able to create several spectacular micro objects. They consist of non-porous, pure copper and feature high mechanical stability.
With the technique it is also possible to print other metals than copper. According to Tomaso Zambelli, group manager at the ETH laboratory of biosensors and bioelectronics, it should even be possible to utilise the process for 3D printing with polymers and compound materials. The next steps will focus on improving the application along with other interested researchers in the academic and industrial world, namely in the watchmaking and automotive industry as well as in medical technology. In particular in rapid prototyping the system could offer benefits over existing methods.