Printing accuracy tracking with 2D optical microscopy and super-resolution metamaterial-assisted 1D terahertz spectroscopy

Abstract

Printable electronics is a promising manufacturing technology for the potential production of low-cost flexible electronic devices, ranging from displays to active wear. It is known that rapid printing of conductive ink on a flexible substrate is vulnerable to several sources of variation during the manufacturing process. However, this process is still not being subjected to a quality control method that is both non-invasive and in situ. To address this issue, we propose controlling the printing accuracy by monitoring the spatial distribution of the deposited ink using terahertz (THz) waves. The parameters studied are the printing speed of an industrial roll-toroll press with flexography printing units and the pre-calibration compression, or expansion factor, for a pattern printed on a flexible plastic substrate. The pattern, which is carefully selected, has Babinet's electromagnetic transmission properties in the THz frequency range. To validate our choice, we quantified the geometric variations of the printed pattern by visible microscopy and compared its accuracy using one-dimensional THz spectroscopy. Our study shows a remarkable agreement between visible microscopic observation of the printing performance and the signature of the THz transmission. Notably, under specific conditions, one-dimensional (1D) THz information from a resonant pattern can be more accurate than two-dimensional (2D) microscopy information. This result paves the way for a simple strategy for non-invasive and contactless in situ monitoring of printable electronics production.

Effects of replacing carbamate with alkyl side chains on the properties and temperature sensing performance of hemi-isoindigo-based polymers

“…Details for the synthesis of monomers and polymers are provided in the supplementary material. The 125 µm thick PET substrates with interdigitated silver (Ag) electrode pairs, which fabrication procedure can be found in the literature [36], were provided by the Natural Sciences and Engineering Research Council (NSERC) of Canada's Strategic Partnership Grants for Networks Program, NSERC-Green Electronics Network.…”

3-dimensional quantitative phase imaging and microscopy of bio and non-bio transparent phase samples using the radial shearing interferometric set-up

“…Using this setup, phase distributions for transparent macroscopic and microscopic objects have been generated with acceptably good fidelity. As in flexible electronics [30], the immediate quantitative imaging of each step in process chemistry or in the field of biomedical imaging science, the quantitative 3-dimensional imaging of transparent phase sample [31] is an extremely essential requirement. So this novel and unique manifestation could be a low-cost alternative to a conventional complex 3-D imaging system and macro & microscopic quantitative phase analysis.…”

Radial shearing interferometry with in-built polarization phase shifting for three-dimensional imaging and quantitative phase analysis of transparent phase objects in macro and microscopic order

“…Quantitative phase imaging delivers the utmost use of this study in the noninvasive bioimaging field [34][35][36] . As in flexible electronics 37 , the immediate quantitative imaging of each step in process chemistry or in the field of imaging science, the quantitative 3dimensional imaging of transparent phase sample 38 is an extremely essential requirement. So this novel and unique manifestation could be the preeminent alternative to a conventional complex 3-D imaging system and macro & microscopic quantitative phase analysis.…”