Coupling of a microfluidic device with a reference cold plasma jet

With liquids being ubiquitous in living organisms, plasma-liquid interaction is of high relevance for applications of plasma science such as water decontamination, agriculture and medicine. A promising diagnostic tool for plasma-liquid interaction lies in microfluidic devices. With the objective of using Lab on a Chip technologies for studying the treatment of cancer by plasma, we developed a platform that enables the coupling of microfluidic devices with an atmospheric pressure plasma jet. The plasma device is based on the μAPPJ. It uses a capacitively coupled discharge excited at 13.56 MHz with two stainless steel electrodes clamped between a glass plate and a microfluidic device. The plasma channel has a volume of 30x1x1 mm³. The effluent of the same dimensions is confined by dielectric walls. The feed gas is helium with variable admixture of O₂, N₂ and H₂O. The 3D-printed microfluidic channel allows high control on the position of the plasma-liquid interface and on the velocity of the liquid. The microfluidic device can be operated with a continuous liquid multiphase flow for increased reactive species transfer.The developed plasma-microfluidic platform is to our knowledge the first demonstration of the coupling of a reference biomedical application-focused plasma jet with a microfluidic device. The platform provides high control over the delivery of plasma-produced reactive oxygen and nitrogen species and is a very powerful diagnostic tool for tailoring plasma reactivity in biomedical applications.