Design-for-testability for paper-based digital microfluidic biochips

Microfluidic biochips have recently emerged as promising solution for biochemical bioassay, which can be classified into two main categories: flow-based microfluidic biochips [1] and digital microfluidic biochips (DMFBs) [2]. However, both of them have to be fabricated in factories with specific equipment, which makes biochips expensive and inflexible. To tackle these problems, paper-based microfluidics essentially combines low-cost paper substrate and sophisticated inkjet printing to realize microfluidics. However, the relative low sensitivity of conventional paper-based microfluidic devices makes it hard to control multi-step assays with high precision. To deal with this problem, the active paper-based digital microfluidic biochips (P-DMFBs) has been developed [3], [4] as a more scalable and cost-effective solution, which is known as “lab-on-paper”.