本研究主要利用簡單、快速的製造方法去發展紙基流體計時器，提供給需要與時間相關之檢測應用。在傳統的比色法中，反應試紙可以直接拿來與色階表作比對，因為樣本濃度的不同使得檢測墊片在經過一連串的化學反應下，呈現的顏色強度會有所不同，再者墊片上產生的顏色變化會隨著時間增加而衰變，使用者將在規定的某段時間內，將檢測墊片與色階表作比對，從而得知樣本濃度值。尿液快速檢測試紙就是用比色法這樣的方式，把多樣檢測結合在同一條試紙上，各墊片不分先後順序同時浸入尿液當中，再依不同時段做顏色比對，藉由此簡單的檢測方式，消費者在家可自行使用，而各檢測墊片應有各自不同的最佳觀測時間進行顏色比對，如此才會使消費者容易分辨出各濃度所對照的顏色。
吾人使用市售葡萄糖與亞硝酸試紙做出其最佳觀測時間，以此提出發展流體計時器裝置是有其必要性，試紙可用紙基流體計時器的時間延遲概念在多樣檢測的情況下做實驗，以兩項檢測為例子，原本需要較長最佳觀測時間之試紙先進行反應，另一方面需要較短最佳觀測時間之試紙，較慢流經檢測區域反應，最後皆可在不用外加的電子計時器下同時進行色階比對，以達到快速、方便、無能源損耗之目的。
本研究用噴蠟印表機及繪圖切割機去製作紙基流體計時器裝置並提出如下的想法。利用不同色素對濾紙有不同的吸附力，以蠟製印表機中的不同色素之蠟塊，結合繪圖軟體的調色盤之CMYK值之改變，在濾紙表面做垂直紙張方向的滲透率改質，往後可再應用於三維紙基流體計時器。一般而言,流體計時器需要得知樣本在濾紙上的速度，而樣本在濾紙上的速度可以藉由Washburn方程式得到，然而吾人在無法得到Washburn方程式部分參數的情況下，透過實驗方式得到資料後，利用Microsoft Excel去產生線性趨勢線並成功預測流體在垂直方向的紙張上所需流動的時間。最後，吾人用噴蠟印表機與繪圖切割機去製作紙基流體計時器，將多層流體紙基計時器簡化成單層紙基流體計時器，並以市售的尿液試紙為例子驗證使用紙基流體計時器而不用外加電子計時器是可行的方法。

A simple and fast method was mainly adapted in this study to develop the paper-based fluidic timer which can provide for colorimetry and others time-related applications that relates with the controlling of the time parameter in the examination process. In traditional colorimetry, chemical pads can be visually deciphered when compared to a gradation table based on the reactions that cause different color intensities to be shown on the test strips from differing sample concentrations. Moreover, color intensity begins to fade and decay after time passes. After allotting a certain period of time, the users compare the chemical pads to the gradation table to assess the concentration value of the sample. Urine rapid testing strips also use colorimetry as previously described by combining several tests on a single plastic strip and then instructing the users to immerse the testing strip into the urine sample regardless of the order and then make color comparisons at separate intervals. By using this simple process, users can conduct the urine test at home by themselves. Each testing strip has an optimum reaction time which means specific testing time for comparison in order to allow the user to easily distinguish the colors of each concentration from the gradation table.
We use the commercially available glucose and nitrite testing strips to get its optimum reaction time in order to demonstrate development of paper-based fluidic timer device as an absolute essential part of the process. Optimal results from testing strips can be obtained through the technique of time-delay on the multi-detection paper-based fluidic timer. For example, by adjusting the lengths of the strips according to reaction times, we placed the pads with slower reaction times on the shorter strips and the pads with quicker reactions on the long strips. This way, we are able to obtain results simultaneously. As a result both of the strips can be processed for color grading comparison simultaneously without the use of extra electronic timing devices. Thus the user is able to achieve quick and easy results with zero energy consumption.
For this study, the paper-based fluidic timer is fabricated by a wax printer and a cutting plotter used as explained in the following explanations. Taking advantage of different pigments attributes to different performance of the paper due to differences in their attraction to the fibers in the paper. Here, we use color palettes which is a function in graphics software to change the CMYK value to control the printing density of the paraffin blocks in order to modify the surface of filter paper. In the future, it can be further applied in three-dimensional paper-based fluidic timer devices. Generally speaking, the result from the paper-based fluidic timer depends on the penetrating velocity of the liquid sample on the filter paper, which can be calculated by Washburn equation. However, we do not know all of the parameters of Washburn’s equation, but can get the necessary data via experiment and produce a linear trend line by using Microsoft Excel and then successfully predict the time of fluid flow on the finger shaped filter paper. Finally, we also developed a paper-based fluidic timer which was fabricated using a wax printer and cutting plotter in our lab and successfully simplified the multi-layered paper-based fluidic timer into a single layered paper-based fluidic timer. Moreover, we took commercially available urine rapid testing strips for verifying the concept of time-delay of paper-based fluidic timer that using our paper-based fluidic timer was a feasible technique to derive results without using an extra electronic timer.

1.Paul Yager, Thayne Edwards, Elain Fu, Kristen Helton, Kjell Nelson, Milton R. Tam and Bernhard H. Weigl, 2006, “Microfluidic diagnostic technologies for global public health.” Nature. 442, 412-418.
2.S.C. Terry, J.H. Jerman and J.B. Angell, 1979, “A Gas chromatographic air analyzer fabricated on a silicon wafer.” IEEE Trans. Electron Devices. ED-26, 12, 1880-1886.
3.Xiaole Maoab and Tony Jun Huang, 2012, “Microfluidic diagnostics for the developing world.” Lab Chip. 8, 1412-1416.
4.Andres W. Martinez, S. T. Phillips, Emanuel Carrilho, Samuel W. Thomas III, Hayat Sindi and G. M. Whitesides, 2008, “Simple telemedicine for developing regions: camera phones and paper-based microfluidic devices for real-time, off-site diagnosis.” Anal. Chem. 80, 3699–3707.
5.Andres W. Martinez, S. T. Phillips, and G. M. Whitesides, 2010, “Diagnostics for the developing world: microfluidic paper-based analytical devices.” Anal. Chem. 82, 3–10.
6.Emanuel Carrilho, Andres W. Martinez and G. M. Whitesides, 2009, “Understanding wax printing: A simple micro-patterning process for paper-based microfluidics.” Anal. Chem. 81, 7091–7095.
7.Yao Lu, Weiwei Shi, Lei Jiang, Jianhua Qin and Bingcheng Lin, 2009, “Rapid prototyping of paper-based microfluidics with wax for low-cost, portable bioassay.” Electrophoresis. 30, 1497–1500.
8.Vincent Leung, Abdel-Aziz M. Shehata, Carlos D.M. Filipe, Robert Pelton, 2010, “Streaming potential sensing in paper-based microfluidic channels. “ Colloids and Surfaces A: Physicochem. Eng. Aspects, 364, 16–18.
9.Z. W. Zhong, Z. P. Wang, G. X. D. Huang, 2012, “Investigation of wax and paper materials for the fabrication of paper-based microfluidic devices” Microsyst. Technol. 18, 649–659.
10.Yao Lu, Weiwei Shi, Jianhua Qin and Bingcheng Lin, 2010, “Fabrication and characterization of paper-based microfluidics prepared in nitrocellulose membrane by wax printing.” Anal. Chem. 82, 329–335.
11.Girish Chitnis, Zhenwen Ding, Chun-Li Chang, Cagri A. Savran and Babak Ziaie, 2011, “Laser-treated hydrophobic paper: An inexpensive microfluidic platform.” Lab Chip. 11, 1161–1165.
12.Andres W. Martinez, S. T. Phillips, and G. M. Whitesides, 2008, “Three-dimensional microfluidic devices fabricated in layered paper and tape. “ Proc. Natl. Acad. Sci. USA. 105, 19606–19611.
13.Andres W. Martinez, S.T. Phillips, M.J. Butte, G.M. Whitesides, 2007, “Patterned paper as a platform for inexpensive, low‐volume, portable bioassays. “Angew. Chem. Int. Ed. 46, 1318–1320
14.Scott A. Klasner, Alexander K. Price, Kurt W. Hoeman, Rashaun S. Wilson, Kayla J. Bell, Christopher T. Culbertson, 2010, ”Paper-based microfluidic devices for analysis of clinically relevant analytes present in urine and saliva. “Anal. Bioanal. Chem. 397, 1821–1829.
15.Xu Li, Junfei Tian, Wei Shen, 2010, “Progress in patterned paper sizing for fabrication of paper-based microfluidic sensors.” Cellulose. 17, 649–659.
16.Xu Li, Junfei Tian, Thanh Nguyen and Wei Shen, 2008, “Paper-based microfluidic devices by plasma treatment.” Anal. Chem. 80, 9131–9134
17.Koji Abe, Koji Suzuki and Daniel Citterio, 2008, “Inkjet-printed microfluidic multianalyte chemical sensing paper.” Anal. Chem. 80, 6928–6934.
18.X Li, J Tian, G Garnier, W Shen, 2010, “Fabrication of paper-based microfluidic sensors by printing.” Colloid Surf. B: Bio-interfaces. 76, 564–570.
19.MS Khan, D Fon, X Li, J Tian, J Forsythe, G Garnier, W Shen, 2010, “Biosurface engineering through ink jet printing.” Colloid Surf. B: Biointerfaces. 75, 441–447
20.J Olkkonen, K Lehtinen, T Erho, 2010, “Flexographically printed fluidic structures in paper.” Anal. Chem. 82, 10246–10250
21.Wijitar Dungchai, Orawon Chailapakul, Charles S. Henry, 2011, “A low-cost, simple, and rapid fabrication method for paper-based microfluidics using wax screen-printing.” Analyst. 136, 77–82.
22.Elain Fu, Barry Lutz, Peter Kauffman and Paul Yager, 2010, “Controlled reagent transport in disposable 2D paper networks.” Lab Chip. 10, 918–920.
23.Lei Ge, Shoumei Wanga, Xianrang Song, Shenguang Ge and Jinghua Yu, 2012, “3D origami-based multifunction-integrated immunodevice: Low-cost and multiplexed sandwich chemiluminescence immunoassay on microfluidic paper-based analytical device.” Lab Chip. 12, 3150–3158.
24.Paul J. Bracher, Malancha Gupta and G. M. Whitesides, 2010, “Patterning precipitates of reactions in paper.” J. Mater. Chem. 20, 5117–5122.
25.J. P. Comer, 1956, “Semiquantitative specific test paper for glucose in urine.” Anal. Chem. 28, 1748–1750.
26.Piia von Lode, 2005, “Point-of-care immunotesting: Approaching the analytical performance of central laboratory methods.” Clin. Biochem. 38, 591–606.
27.N Ratnarathorn, O Chailapakul, CS Henry, W.Simple Dungchai, 2012, “Silver nanoparticle colorimetric sensing for copper by paper-based devices.” Talanta, 99, 552–557.
28.H Noh, S.T. Phillips, 2010, “Fluidic timers for time-dependent, point-of-Care assays on paper.” Anal. Chem. 82, 8071–8078.
29.Erin M Fenton, Monica R Mascarenas, Gabriel P López, Scott S Sibbett, 2009, “Multiplex lateral-flow test strips fabricated by two-dimensional shaping.” ACS Appl. Mater. Inter. 1, 124–129.
30.Qiaohong He, Cuicui Ma, Xianqiao Hu and Hengwu Chen, 2013, “Method for fabrication of paper-based microfluidic devices by alkylsilane self-assembling and UV/O3‑patterning.” Anal. Chem. 85, 1327−1331.
31.Barry R. Lutz, Philip Trinh, Cameron Ball, Elain Fu, Paul Yager, 2011, “Two-dimensional paper networks: programmable fluidic disconnects for multi-step processes in shaped paper.” Lab Chip. 11, 4274–4278.
32.Attila Gáspára, István Bácsib, 2009, “Forced flow paper chromatography: A simple tool for separations in short time.” Microchemical Journal. 92, 83–86.
33.E Fu, SA Ramsey, P Kauffman, Barry Lutz, Paul Yager, 2011, “Transport in two-dimensional paper networks.” Microfluid Nanofluid, 10, 29–35.