Integration of electrowetting technology inside an all-glass microfluidic network

This paper presents a low temperature technological process able to integrate an all-glass microfluidic network with an ElectroWetting On Dielectric (EWOD) structure for the digital handling of liquids. The fluidic channels result from the wet-etching of the glass, while the electrodes necessary for the droplet movement are deposited on the bottom and top surfaces of the microfluidic structure. The bottom electrodes are produced by a selective and sequential photolithographic pattern of a stack of metals, insulation layer and hydrophobic film. The top common electrode is made by a continuous transparent conductive oxide, covered by a hydrophobic layer. Compatibility of the technological steps and mechanical robustness of the proposed device have been tested designing and fabricating a microfluidic network integrating a central chamber, with a volume of about 9 μl, two reservoirs, two microfluidic channels and 26 EWOD electrodes. The maximum temperature reached during the device fabrication was 330°C, which is two times lower than the one used for the anodic bonding of glass-based microfluidic network

Design and development of a lab-on-chip for biomedical analysis based on electrowetting on dielectric technique

The purpose of this thesis research project has been the development of a compact and versatile optoelectronic platform able to implement all the functionalities needed for a lab-on-chip operation. The project includes also the development of the electronics needed for the control of the system. In particular, the proposed platform includes three different modules designed for the fluid handling through the ElectroWetting On Dielectric (EWOD) technique, the thermal sample treatment and optical detection. These modules incorporate thin film microelectronic devices (such as photosensors and interferential filters for the optical detection, or heaters and temperature sensors for the sample treatments) on glass substrates connected to the electronic microcontrollers. Moreover, the use of handling techniques which avoid the use of pumps and syringes led to a portable, high-sensitive and low-power consumption lab-on-chip device. All of the modules have been designed, fabricated and tested separately. Finally, a device integrating all of the functionalities mentioned before has been designed for the development of a multifunctional platform able to perform a “true” lab-on-chip biomolecular system