Microfluidics can precisely control and manipulate micro-scale fluids, and are also known as lab-on-a-chip or micro total analysis systems. Microfluidics have huge application potential in biology, chemistry, and medicine, among other fields. Coupled with a suitable detection system, the detection and analysis of small-volume and low-concentration samples can be completed. This paper reviews an optical imaging system combined with microfluidics, including bright-field microscopy, chemiluminescence imaging, spectrum-based microscopy imaging, and fluorescence-based microscopy imaging. At the end of the article, we summarize the advantages and disadvantages of each imaging technology.

Digital microfluidics system is a powerful platform to realise true lab-on-a-chip. While most biological applications have delicate temperature requirements, integration of a thermal system with microfluidics has become an obstacle for system minimization for applications in point-of-cares. In this paper, we developed a heating plate on glass based on thin-film technology, which is fully compatible with glass substrate-based digital microfluidic chip. The thin-film heating plate and the digital microfluidic chip were controlled with a customized driver circuit. We have carried out characterization experiments to verify the on-chip temperature uniformity and heating rate. We have demonstrated both Polymerase Chain Reaction and Recombinase Polymerase Amplification experiments with the proposed system. This work opens up a new way for portable glass-based digital microfluidic chips with a fully integrated thermal system.