Abstract

A simple and novel method is proposed for the fabrication of aspherical SU-8 microlens arrays with a wide range of tunable focal lengths utilizing a soft SU-8 stamping process and an electro-static pulling method. In the proposed approach, an SU-8 stamp incorporating a micro-nozzle array and a reservoir containing unexposed SU-8 is fabricated on a glass substrate using a dose-controlled exposure process. Microlens arrays with diameters ranging from 20 to 500 μm and various radii of curvature are successfully fabricated using the proposed method. The low surface roughness (Ra = 3.84 nm) and high dimensional uniformity of the SU-8 microlens arrays (variation < 5% designed diameter) confirm both the optical quality of the individual microlenses and the general feasibility of the fabrication method. The innovative fabrication method proposed in this study provides a simple and efficient means of producing high quality aspherical microlens arrays with tunable focal lengths.

© 2010 OSA

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References

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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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2010

2009

2008

K. Y. Hung, F. G. Tseng, and T. H. Liao, “Electrostatic-force-modulated microaspherical lens for optical pickup head,” J. Microelectromech. Syst. 17(2), 370–380 (2008).
[CrossRef]

S. M. Kuo and C. H. Lin, “The fabrication of non-spherical microlens arrays utilizing a novel SU-8 stamping method,” J. Micromech. Microeng. 18(12), 125012 (2008).
[CrossRef]

H. Ren and S. T. Wu, “Tunable-focus liquid microlens array using dielectrophoretic effect,” Opt. Express 16(4), 2646–2652 (2008).
[CrossRef] [PubMed]

2007

L. T. Jiang, T. C. Huang, C. R. Chiu, C. Y. Chang, and S. Y. Yang, “Fabrication of plastic microlens arrays using hybrid extrusion rolling embossing with a metallic cylinder mold fabricated using dry film resist,” Opt. Express 15(19), 12088–12094 (2007).
[CrossRef] [PubMed]

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

2005

2004

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

2003

2002

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

2000

1994

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

1993

1990

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Bu, J.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

M. He, X. C. Yuan, N. Q. Ngo, J. Bu, and V. Kudryashov, “Simple reflow technique for fabrication of a microlens array in solgel glass,” Opt. Lett. 28(9), 731–733 (2003).
[CrossRef] [PubMed]

Cao, Z. L.

Chang, B. W.

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

Chang, C. Y.

Chang, G. L.

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

Chen, C. F.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Chen, T.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

Chen, Y. K.

Cheng, J. W. J.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Chiu, C. R.

Cox, W. R.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

Daly, D.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Davies, N.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Esener, S. C.

Fan, C. C.

Goto, K.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

Hartmann, D. M.

Hayes, D. J.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

He, M.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

M. He, X. C. Yuan, N. Q. Ngo, J. Bu, and V. Kudryashov, “Simple reflow technique for fabrication of a microlens array in solgel glass,” Opt. Lett. 28(9), 731–733 (2003).
[CrossRef] [PubMed]

Ho, J. R.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Hsieh, C. C.

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

Huang, T. C.

Hung, K. Y.

K. Y. Hung, C. C. Fan, F. G. Tseng, and Y. K. Chen, “Design and fabrication of a copolymer aspheric bi-convex lens utilizing thermal energy and electrostatic force in a dynamic fluidic,” Opt. Express 18(6), 6014–6023 (2010).
[CrossRef] [PubMed]

K. Y. Hung, F. G. Tseng, and T. H. Liao, “Electrostatic-force-modulated microaspherical lens for optical pickup head,” J. Microelectromech. Syst. 17(2), 370–380 (2008).
[CrossRef]

Hutley, M. C.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Jiang, L. T.

Kibar, O.

Kudryashov, V.

Kuo, J. N.

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

Kuo, S. M.

S. M. Kuo and C. H. Lin, “The fabrication of non-spherical microlens arrays utilizing a novel SU-8 stamping method,” J. Micromech. Microeng. 18(12), 125012 (2008).
[CrossRef]

Kurihara, K.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

LaCosse, J.

Lazare, S.

Lee, G. B.

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

Liao, T. H.

K. Y. Hung, F. G. Tseng, and T. H. Liao, “Electrostatic-force-modulated microaspherical lens for optical pickup head,” J. Microelectromech. Syst. 17(2), 370–380 (2008).
[CrossRef]

Lin, C. H.

S. M. Kuo and C. H. Lin, “The fabrication of non-spherical microlens arrays utilizing a novel SU-8 stamping method,” J. Micromech. Microeng. 18(12), 125012 (2008).
[CrossRef]

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

MacFarlane, D. L.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

Mihailov, S.

Mitsugi, S.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

Nanri, K.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

Narayan, V.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

Ngo, N. Q.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

M. He, X. C. Yuan, N. Q. Ngo, J. Bu, and V. Kudryashov, “Simple reflow technique for fabrication of a microlens array in solgel glass,” Opt. Lett. 28(9), 731–733 (2003).
[CrossRef] [PubMed]

Nikolov, I. D.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

Powell, K. D.

Ren, H.

Shih, T. K.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Stevens, R. F.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Su, G. D. J.

Sung, C. K.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Tao, S. H.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

Tatum, J. A.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

Toshiyoshi, H.

Tseng, F. G.

K. Y. Hung, C. C. Fan, F. G. Tseng, and Y. K. Chen, “Design and fabrication of a copolymer aspheric bi-convex lens utilizing thermal energy and electrostatic force in a dynamic fluidic,” Opt. Express 18(6), 6014–6023 (2010).
[CrossRef] [PubMed]

K. Y. Hung, F. G. Tseng, and T. H. Liao, “Electrostatic-force-modulated microaspherical lens for optical pickup head,” J. Microelectromech. Syst. 17(2), 370–380 (2008).
[CrossRef]

Urey, H.

Wang, K. Y.

Wu, M. C.

Wu, S. T.

Yang, S. Y.

L. T. Jiang, T. C. Huang, C. R. Chiu, C. Y. Chang, and S. Y. Yang, “Fabrication of plastic microlens arrays using hybrid extrusion rolling embossing with a metallic cylinder mold fabricated using dry film resist,” Opt. Express 15(19), 12088–12094 (2007).
[CrossRef] [PubMed]

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

Yao, H. T.

Yu, W. X.

Yuan, X. C.

Yuan, X.-C.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

Zhan, Z. X.

Appl. Opt.

IEEE Photon. Technol. Lett.

D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, “Microjet Fabrication of Microlens Arrays,” IEEE Photon. Technol. Lett. 6(9), 1112–1114 (1994).
[CrossRef]

J. Lightwave Technol.

J. Microelectromech. Syst.

K. Y. Hung, F. G. Tseng, and T. H. Liao, “Electrostatic-force-modulated microaspherical lens for optical pickup head,” J. Microelectromech. Syst. 17(2), 370–380 (2008).
[CrossRef]

J. Micromech. Microeng.

C. H. Lin, G. B. Lee, B. W. Chang, and G. L. Chang, “A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist,” J. Micromech. Microeng. 12(5), 590–597 (2002).
[CrossRef]

S. M. Kuo and C. H. Lin, “The fabrication of non-spherical microlens arrays utilizing a novel SU-8 stamping method,” J. Micromech. Microeng. 18(12), 125012 (2008).
[CrossRef]

J. N. Kuo, C. C. Hsieh, S. Y. Yang, and G. B. Lee, “An SU-8 microlens array fabricated by soft replica molding for cell counting applications,” J. Micromech. Microeng. 17(4), 693–699 (2007).
[CrossRef]

J. Opt. A, Pure Appl. Opt.

M. He, X.-C. Yuan, N. Q. Ngo, J. Bu, and S. H. Tao, “Single-step fabrication of a microlens array in sol-gel material by direct laser writing and its application in optical coupling,” J. Opt. A, Pure Appl. Opt. 6(1), 94–97 (2004).
[CrossRef]

Meas. Sci. Technol.

D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The Manufacture of Microlenses by Melting Photoresist,” Meas. Sci. Technol. 1(8), 759–766 (1990).
[CrossRef]

Opt. Express

Opt. Lett.

Opt. Rev.

K. Kurihara, I. D. Nikolov, S. Mitsugi, K. Nanri, and K. Goto, “Design and fabrication of microlens array for near-field vertical cavity surface emitting laser parallel optical head,” Opt. Rev. 10(2), 89–95 (2003).
[CrossRef]

Sens. Actuators A Phys.

J. R. Ho, T. K. Shih, J. W. J. Cheng, C. K. Sung, and C. F. Chen, “A novel method for fabrication of self-aligned double microlens arrays,” Sens. Actuators A Phys. 135(2), 465–471 (2007).
[CrossRef]

Other

V. Fakhfouri, N. Cantale, G. Mermoud, J. Y. Kim, D. Boiko, E. Charbon, A. Martinoli, and J. Brugger, “Inkjet printing of SU-8 for polymer-based MEMS a case study for microlenses,” in Proceedind of Micro Electro Mechanical Systems, (Institute of Electrical and Electronics Engineers, Sorrento, 2008), 407–410.

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Figures (5)

Fig. 1
Fig. 1

Schematic illustration of aspherical SU-8 microlens array fabrication concept: (A) SU-8 lens molding, (B) electrostaic pulling.

Fig. 2
Fig. 2

SEM images of fabricated microlens array with excellent surface flatness: (A) semispherical microlens array with diameter of 300 μm (molding temperature = 65°C), (B) hexagonal microlens array with diameter of 100 μm (molding temperature = 70°C). (C) microlens without electrostatic pulling and (D) after electro-static pulling at 2500 V. OM image showing the focus behavior of microlens arrays fabricated under different electro-static pulling voltages. (E) 0 V and (F) 2500 V.

Fig. 3
Fig. 3

Variation of micro-lens height with stamping temperature as function of lens diameter.

Fig. 4
Fig. 4

(A) Scanned surface profiles of 500 μm microlens fabricated at 60°C and then reflowed at temperatures between 70°C and 100°C. (B) Measured optical behavior of microlens arrays fabricated under different electro-static pulling voltages from 0 V/cm to 32500 V/cm. Note that these profiles were obtained by analyzing the lens contours of the SEM images using commercial software of Matlab®.

Fig. 5
Fig. 5

(A) Photographs of light emitted from a spherical microlens array with a lens diameter of 300 μm and a radius of curvature of 230 μm, (B) measured intensity profiles. Note that “D” in (A) denotes spot diameter and “I” in (B) denotes spot intensity. Note that this microlens array was fabricated with a stamping temperature of 70°C and without the electro-static pulling process.

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