TY - CONF

T1 - Nanoimprinted polymer chips for light induced local heating of liquids in micro- and nanochannels

A1 - Thamdrup,Lasse Højlund

A1 - Pedersen,Jonas Nyvold

A1 - Flyvbjerg,Henrik

A1 - Larsen,Niels Bent

A1 - Kristensen,Anders

AU - Thamdrup,Lasse Højlund

AU - Pedersen,Jonas Nyvold

AU - Flyvbjerg,Henrik

AU - Larsen,Niels Bent

AU - Kristensen,Anders

PB - S P I E - International Society for Optical Engineering

PY - 2010

Y1 - 2010

N2 - A nanoimprinted polymer chip with a thin near-infrared absorber layer that enables light-induced local heating (LILH) of liquids inside micro- and nanochannels is presented. An infrared laser spot and corresponding hot-spot could be scanned across the device. Large temperature gradients yield thermophoretic forces, which are used to manipulate and stretch individual DNA molecules confined in nanochannels. The absorber layer consists of a commercially available phthalocyanine dye (Fujifilm), with a narrow absorption peak at approximately 775 nm, dissolved in SU-8 photoresist (Microchem Corp.). The 500 nm thick absorber layer is spin-coated on a transparent substrate and UV exposed. Microand nanofluidic channels are defined by nanoimprint lithography in a 1.5 μm thick layer of low molecular weight polymethyl methacrylate (PMMA, Microchem Corp.), which is spin coated on top of the absorber layer. We have used a previously developed two-level hybrid stamp for replicating two V-shaped microchannels (width=50 μm and height = 900 nm) bridged by an array of 200 nanochannels (width and height of 250 nm). The fluidic channels are finally sealed with a lid using PMMA to PMMA thermal bonding. Light from a 785 nm laser diode was focused from the backside of the chip to a spot diameter down to 5 ..m in the absorber layer, yielding a localized heating (Gaussian profile) and large temperature gradients in the liquid in the nanochannels. A laser power of 38 mW yielded a temperature of 40°C in the center of a 10 μm 1/e diameter. Flourescence microscopy was performed from the frontside.

AB - A nanoimprinted polymer chip with a thin near-infrared absorber layer that enables light-induced local heating (LILH) of liquids inside micro- and nanochannels is presented. An infrared laser spot and corresponding hot-spot could be scanned across the device. Large temperature gradients yield thermophoretic forces, which are used to manipulate and stretch individual DNA molecules confined in nanochannels. The absorber layer consists of a commercially available phthalocyanine dye (Fujifilm), with a narrow absorption peak at approximately 775 nm, dissolved in SU-8 photoresist (Microchem Corp.). The 500 nm thick absorber layer is spin-coated on a transparent substrate and UV exposed. Microand nanofluidic channels are defined by nanoimprint lithography in a 1.5 μm thick layer of low molecular weight polymethyl methacrylate (PMMA, Microchem Corp.), which is spin coated on top of the absorber layer. We have used a previously developed two-level hybrid stamp for replicating two V-shaped microchannels (width=50 μm and height = 900 nm) bridged by an array of 200 nanochannels (width and height of 250 nm). The fluidic channels are finally sealed with a lid using PMMA to PMMA thermal bonding. Light from a 785 nm laser diode was focused from the backside of the chip to a spot diameter down to 5 ..m in the absorber layer, yielding a localized heating (Gaussian profile) and large temperature gradients in the liquid in the nanochannels. A laser power of 38 mW yielded a temperature of 40°C in the center of a 10 μm 1/e diameter. Flourescence microscopy was performed from the frontside.

U2 - 10.1117/12.860221

DO - 10.1117/12.860221

JO - Proceedings of the SPIE - The International Society for Optical Engineering

JF - Proceedings of the SPIE - The International Society for Optical Engineering

SN - 1605-7422

VL - 7764

SP - 77640I

ER -