fabrication of metal microneedle based on laser …
TRANSCRIPT
FABRICATION OF METAL MICRONEEDLE BASED ON LASER ABLATION USING TWISTED LIGHT WITH SPINSCPY491 Undergraduate Physics Seminar 21 September 2021st
Natwadee Sarapong 6105161, 4 year undergraduate student, Department of Physics, Faculty of Science, Mahidol University
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Faculty of Science
https://www.chula.ac.th/en/news/12824/
Introduction
Methodology
Results and Discussion
Conclusion
OUTLINES- What is microneedle - Laser ablation
- Twisted light with spin - Experimental Set Up
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Microneedles are the technique of transdermal drug delivery which are ;
- pain free
- no damaging blood vessels
- higher weights of drug
- drug delivery with differing features
Suh H, et al., 2014
INTRODUCTION
3
WHAT IS MICRONEEDLE ?
INTRODUCTION
4
There are several type of microneedles ; solid removable, dissolving, holow, hydrogel-forming and coated microneedles
Rzhevskiy, A.S., et al., 2018
Laser ablation is a promising top-down process for material precessing by irradiating it with laser beam.
INTRODUCTION
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LASER ABLATION
For example:
- Microdrilling - Cutting - Scribing
- Metals - Dielectric materials - Semiconductors
into
INTRODUCTION
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LASER ABLATION
- Energy is first transferred to the electron system, and then to the lattice system.
- Its temperature increases phase transition occurs from solid state to liquid, gaseous, and plasma states
- Phase transition occurs from solid state to plasma states
Preparation of nanoparticles by laser in solution https://en.wikipedia.org/wiki/Laser_ablation
INTRODUCTION
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LASER ABLATION At high laser flux, the material is typically converted to a plasma.
- pulsed laser
- continuous wave laser with high intensity
Wavelength of laser is approximately 200nm
HIGH COST
Types of laser that can contribute the ablation :
Preparation of nanoparticles by laser in solution https://en.wikipedia.org/wiki/Laser_ablation
The surface processed using twisted light caused less debris in comparison with one using untwisted annular nanosecond pulses.
INTRODUCTION
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LASER ABLATION
Consider the laser pulse…
Normal laser twisted laser (helical wavefront) : nanosecond optical vortex pulses
with orbital angular momentum (L) and an annular intensity in the transverse plane
LOWER COST
A total angular momentum (J) equal to the vector sum of the orbital (L) and spin (S) angular momentum.
The direction of the vortex with L = 1 is the same as the circular polarization,
The opposite direction contributes
|J | = |L | + |S | = 2
|J | = |L | − |S | = 0
METHODOLOGY
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Definition of the total angular momentum of twisted light with spin.
METHODOLOGY
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Experimental Set UpMetal laser ablation using nanosecond optical vortex pulses with orbital angular momentum was performed.
Equipments:
- SPP : spiral phase plate - QWP : quarter-wave plate - ~1 mm thick tantalum plate
Why Ta?Ta has low ablation threshold in comparison with other metals, which makes the ablation become easier.
METHODOLOGY
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Experimental Set Up>> How the needle is formed?
Model for a microneedle fabrication by 'twisted-light with spin' laser ablation
RESULTS
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Laser-scanning microscope images of processed surfaces pumped by
twisted light
a protuberance appears at the center of the processed surface
Debris caused by plasma spin
RESULTS
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Experimental data obtained for a total angular momentum of 2
{Ratio of the length of the protuberance to its thickness}
RESULTS
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Fabrication of a two-dimensional 5 × 6 microneedle array by twisted-light laser ablation, using 2 twisted light pulses
Average length = 11 μm
Tip diameter = 0.5 μm
The standard deviations in the length and tip diameter are estimated to be 1.9 and 0.15 μm, respectively.
CONCLUSION
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Two-dimensional microneedle arrays fabrication >>> All needles have uniformly good quality.
This method contributes high-speed nano-imaging, energy-saving displays.
demonstration of microneedle fabrication using laser ablation by nanosecond twisted light with spin
Comparing the total angular momentum of J = 2 and J = 0, J = 0 gives better results that:
- higher aspect ratio
- less debris
demonstration of microneedle fabrication using laser ablation by nanosecond twisted light with spin
Using J = 2 twisted light with spin and observing the resulting of pulses number
“there is the optimal shots (around 3-4 shots)”
REFERENCES
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Takashige Omatsu, Keisuke Chujo, Katsuhiko Miyamoto, Masahito Okida, Kazuki Nakamura, Nobuyuki Aoki, and Ryuji Morita, "Metal microneedle fabrication using twisted light with spin," Opt. Express 18, 17967-17973 (2010)
Junichi Hamazaki, Ryuji Morita, Keisuke Chujo, Yusuke Kobayashi, Satoshi Tanda, and Takashige Omatsu, "Optical-vortex laser ablation," Opt. Express 18, 2144-2151 (2010)
Hongkun Huang, Jiancheng Lai, Jian Lu, and Zhenhua Li , "Pulsed laser ablation of bulk target and particle products in liquid for nanomaterial fabrication", AIP Advances 9, 015307 (2019) https://doi.org/10.1063/1.5082695