• He, Peijun
• Galanis, Panagiotis
• Sones, Collin L.
• Katis, Ioannis
• Eason, Robert W.

Abstract

In recent years, the requirements for easy-to-use, low-cost and accurate diagnostic solutions have led to a rapid progress in the research of POC diagnostic devices, especially lab-on-chip (LOC) type POC devices[1]. Paper-based microfluidic devices, which are regarded as a low-cost alternative to conventional POC diagnostics tools, have also been popularly studied in the last decade because of the following many advantages they offer - affordable, mass producible, disposable via incineration etc. [2].<br/><br/>As one of the simplest and well-established formats of paper-based devices, lateral flow devices (LFDs), are currently the primary means for the detection of a variety of analytes and the most common example of such a device is the pregnancy test that can be easily bought over the counter of a pharmacy or local shop. With regardstesting in remote inaccessible locations or in homes, they also inherently provide many advantages such as being mass-producible, and hence affordable in their costs equipment free, require no external power to operate and easily disposable.<br/><br/>However, they do have a some limitations that restrict the creation and further development of these LFDs into devices with more complex functionalities [3]. The physical properties inherent to the porous substrates that are used to build these devices offer limited control over fluid transport, especially with regards the flow-rate and direction of the fluid flow. This presents a critical drawback which limits their sensitivity and limit of detection [4]. On the other hand, multiplexing, which is defined as analysis of multiple analytes simultaneously under the same set of conditions is regarded as one of the vital parameters for increased efficiency of diagnosis and treatment,is also currently, comparatively, not easily achievable for LFDs [5].<br/><br/>In this article, we propose novel solutions to overcome both these limitations via precisely patterning the flow-path of a single LFD using our proprietary laser direct-write (LDW) technique. These allows better liquid handling and transportation within single/multiple flow-path of an LFD and therefore leads to improvements of their performance and also implementation of additional functionalities such as multiplexing.

Topics

• porous
• impedance spectroscopy