Fabrication of Concave and Convex Micro-Optical Elements With Polymer for Free-Space Micro-Optical Bench

Chollet, Franck; Low, Chun Hong; Lee, Sok Kim; Yang, Chun

doi:10.1142/s1465876303001484

Cited by 4 publications

(8 citation statements)

References 3 publications

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“…The isotropic profile of the microneedles was fabricated using two effects: flowing of thick photoresist mask and notching effect of the reflected charges on mask. It is a well-known property of the thick photoresist that it reflows when it is heated at 120 °C [27]. The modification of the vertical wall of the patterned photoresist can reflect the charges (ions and radials) during the RIE process and in this way generates the etched profile under the oxide mask.…”

Section: Design and Fabricationmentioning

confidence: 99%

Transdermal drug delivery: Microfabrication insights

Iliescu

Chen

Wei

et al. 2009

2009 International Semiconductor Conference

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The paper presented an enhancement solution for transdermal drug delivery using microneedles array with biodegradable tips. The microneedles array was fabricated by using deep reactive ion etching (DRIE) and the biodegradable tips were made to be porous by electrochemical etching process. The porous silicon microneedle tips can greatly enhance the transdermal drug delivery in a minimum invasion, painless, and convenient manner, at the same time; they are breakable and biodegradable. Basically, the main problem of the silicon microneedles consists of broken microneedles tips during the insertion. The solution proposed is to fabricate the microneedle tip from a biodegradable material -porous silicon. The silicon microneedles are fabricated using DRIE notching effect of reflected charges on mask. The process overcomes the difficulty in the undercut control of the tips during the classical isotropic silicon etching process. When the silicon tips were formed, the porous tips were then generated using a classical electrochemical anodization process in MeCN/HF/H2O solution. The paper presents the experimental results of in vitro release of calcein and BSA with animal skins using a microneedle array with biodegradable tips. Compared to the transdermal drug delivery without any enhancer, the microneedle array had presented significant enhancement of drug release.

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Section: Design and Fabricationmentioning

confidence: 99%

Transdermal drug delivery: Microfabrication insights

Iliescu

Chen

Wei

et al. 2009

2009 International Semiconductor Conference

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show abstract

“…The isotropic profile of the microneedles was fabricated using two effects: flowing of the thick photoresist mask and notching effect of the reflected charges on the mask. It is a well-known property of the thick photoresist that it reflows when it is heated at 120°C (Zhu et al 2000;Chollet et al 2003). The modified vertical wall of the patterned photoresist can reflect the charges (ions and radials) during the RIE process and in this way generates the etching profile under the oxide mask.…”

Section: Design and Fabrication Of Microneedlesmentioning

confidence: 99%

Silicon microneedle array with biodegradable tips for transdermal drug delivery

et al. 2008

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This paper presents the fabrication process, characterization results and basic functionality of silicon microneedle array with biodegradable tips for transdermal drug delivery. In order to avoid the main problems related to silicon microneedles; the breaking of the top part of the needles inside the skin, a simple solution can be the fabrication of microneedle array with biodegradable tips. A silicon microneedle array was fabricated by deep reactive ion etching (RIE), using the photoresist reflow effect and RIE notching effect. The biodegradable tips were successfully realized using the electrochemical anodization process that selectively generated porous silicon only on the top part of the skin. The porous tips can be degraded within a few weeks if some of them are broken inside the skin during the insertion and release process. The paper presents also the results of in vitro release of calcein with animal skins using a microneedle array with biodegradable tips. Compared to the transdermal drug delivery without microneedle enhancer, the microneedle array had presented significant enhancement of drug release.

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“…PC-based collimation lenses can be made much smaller than traditional collimation lenses ͑with curved surfaces͒ and production of such lenses by micromachining techniques is straightforward and inexpensive. These advantages enable the mass-production of collimation devices at the microscale, where traditional convex and concave lenses 17 are extremely difficult to fabricate.…”

Section: Introductionmentioning

confidence: 99%

Photonic crystal composites-based wide-band optical collimator

Shi

Juluri

Lin

et al. 2010

Journal of Applied Physics

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Photonic crystal ͑PC͒ composites are sequenced series of PCs that feature the same periods but different filling fractions. By properly tuning the filling fractions of the individual PCs and merging the working band of each PC into a continuous frequency range, wide-band self-collimation of optical signals can be realized. The band diagrams and the equal-frequency contours of the PC structures were calculated through the plane wave expansion method and the finite-difference time-domain method was employed to simulate the propagation of electromagnetic waves through the PC structures. Our results show that while a single PC can only collimate optical waves over a narrow frequency range, a PC composite exhibits a much wider collimation band. Such a wide-band optical collimation lens can be useful in applications that demand directional optical energy flow over a long distance, such as optical imaging and biosensing.

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Fabrication of Concave and Convex Micro-Optical Elements With Polymer for Free-Space Micro-Optical Bench

Cited by 4 publications

References 3 publications

Transdermal drug delivery: Microfabrication insights

Transdermal drug delivery: Microfabrication insights

Silicon microneedle array with biodegradable tips for transdermal drug delivery

Photonic crystal composites-based wide-band optical collimator

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