A simple and low cost method to fabricate NOA microfluidic chips

09月2015日

Gabriele Pitingolo^一,Raffaele Vecchione^1,3and Paolo A.Netti^1,2,3

^一Center for Advanced Biomaterials for Healthcare,Istituto Italiano di tecnologia (IIT@CRIB),Largo Barsanti e Matteucci,53,80125,NaplesItaly.

²Dipartimento di Ingegneria Chimica,dei Materiali e della Produzione Industriale D.I.C.MA.P.I,那不勒斯第二费德里科大学Naples 80125，Italy.

³里切卡中心跨学科生物材料研究所（Crib）意大利di那不勒斯费德里科•二世,p.le Tecchio 80,Naples80125,Italy

为什么这个有用？

微流控芯片通常由硅或玻璃制成，这就存在相对昂贵的缺点。time consuming and has limitations to the geometries that can be realized.PMMA is an optimal solution to overcome these aspects but it presents a low chemical resistance to organic solvents and aggressive chemicals

诺兰光学粘合剂60（“NOA60”）是透明的，colorless,liquid photopolymer that cures when exposed to ultraviolet light^一.Surface bonding can be activated with light therefore monolithic and transparent devices especially useful for optical elements can be realized.In particular,the use of NOA 60 eliminates premixing,干燥，or heat curing operations common to other optical adhesive systems.Curing time is a matter of minutes and is dependent upon the thickness applied and the energy of ultraviolet light available.Dupont and colleagues have recently developed a NOA microfluidic channel via a photolithography multistep method that presents a long time process².

Here,we demonstrate the possibility to micromachine already cured NOA substrates by micromilling that is much easier and cheaper than photolithographic techniques for fabrication of microchannels or microstructures in general.In addition,by micromilling it is possible to easily drill and make open channels in NOA substrates if needed.Also,如果要粘合的两层上有显微结构，如果一层的显微结构的特征尺寸低于25微米，而一层的特征尺寸高于此值，则可以通过光刻技术制备一个基底，通过以下粘合的显微加工制备另一个基底。saving time and money.

我需要什么？

Fully cured PDMS mold
Norland Optical Adhesive 60
UV light (E-Series Ultraviolet Hand Lamps)
Micromachining machine
Oxygen plasma machine
夹紧

What do I do?

1。将液态光聚合物NOA倒入覆盖整个表面的预制PDMS模具中（图1a）。After a few minutes to stabilize the liquid polymer put the PDMS mold under UV light for 30 minutes at a 365 nm wavelength (fig.1B).

2.固化时间过后，NOA substrate is ready to use;to fabricate a microfluidic chip two NOA substrates are prepared.NOA substrates are replicated onto flat PDMS surfaces exploiting the flexibility of the PDMS mold as shown in figures 2A and 2B.

三。Take the NOA substrate and mill a channel and related inlet/outlet holes using a micromilling machine (Minitech CNC Mini-Mill) (fig.3A-3B),the certified positioning accuracy of the three-axis are 12″ / 300mm in x-axis,Y轴9英寸/228mm，and 9″ / 228mm in z-axis.为了将实验的不确定性降到最低，在第2点中预成型的NOA基板在研磨前进行平滑处理。

4.Prepare the NOA channel (clean with water and dry with an absorbent cloth) and treat the channel and top layer by exposing to oxygen plasma for 60s,在小于0.1托的压力下，等离子体功率为20W（图4a）。夹住两个基板，将夹住的通道置于紫外光下1小时，完成粘合过程（图4b）。