researchers working on Rice materials are developing nanostructures of silicons with state of the art 3D printer, showcasing a novel method in making microscale electronic,
mechanical and photonic devices from the bottom up.
The device can be doped and its crystal structures adjusted for different functions.
The research was led by Jun Lou, a professor of materials and Nanoengineering at the George R. Brown School of Engineering and appears in the journal nature material.
Based on the basic semiconducting substrate for micro-processes which has been used for decades,
silicon is the bedrock of the electronics industry.
The study addresses the challenges facing top-down manufacturing by turning the process on its head.
According to the head of research Jun Lou. ” it is very hard to make complex 3D geometrics with regular photolithography methods,
However,
it isn’t exactly eco friendly because of the various chemicals involved in the processes, and even with all those steps, some structures are too complex to develop.
He further added,
” In Principle, we can print Arbitrary 3D shapes, which holds a lot of potential for exotic photonic devices, Which is what we are trying to demonstrate.”
The lab makes use of a 2 photon polymerization process to print structures with lines only several 100 nanometres wide, smaller than the wavelength of light.
The Process
Lasers write the lines by prompting the ink to absorb the two photons, setting up free radical polymerization of the material.
According to the co-lead author of the study Boyu Zhang
” regular polymerization requires polymer monomers and photoinitiators, a set of molecules able to absorb light and generate free radicals,
that mostly use ultraviolet light in 3Dprinting and to cure coatings in dental applications.”
their process involves two photoinitiator absorbing photons simultaneously which involves massive energy.
furthermore only a minute part of this energy causes polymerization,
and that is in a very tiny space.
That is why this process enables us to go beyond the diffraction limit of light.
The additive manufacturing process would allow the Rice lab to develop a unique ink
the research team on the study created resins containing nanospheres of silicon dioxide doped with polyethene glycol to make them soluble.
Source: Rice Uni
