Compact Three-Dimensional Digital Microfluidic Platforms with Programmable Contact Charge Electrophoresis Actuation

Abstract

Digital microfluidics (DMF) has garnered considerable interest as a straightforward, rapid, and programmable technique for controlling microdroplets in various biological, chemical, and medicinal research disciplines. This study details the construction of compact and lowcost 3D DMF platforms with programmable contact charge electrophoresis (CCEP) actuations by employing electrode arrays composed of a small commercial pin socket and a 3D-printed housing. We demonstrate basic 3D droplet manipulation on the platform, including horizontal and vertical transport via lifting and climbing techniques, and droplet merging. Furthermore, phenolphthalein reaction and precipitation process are evaluated using the proposed 3D DMF manipulations as a proof of concept for chemical reaction-based analysis and synthesis. The threshold voltage (or electrical field) and maximum vertical transport velocity are quantified as a function of applied voltage and electrode distance to determine the CCEP actuation conditions for 3D droplet manipulations. The ease of manufacturing and flexibility of the proposed 3D DMF platform may provide an effective technique for programmable 3D manipulation of droplets in biochemical and medical applications, such as biochemical analysis and medical diagnostics.

Magnetically Driven Manipulation of Nonmagnetic Liquid Marbles: Billiards with Liquid Marbles

“…This is an interesting phenomenon with rich underlying physics that opens the door for future studies for a better understanding of the dynamics of the collision. Moreover, a 3D digital microfluidic manipulation can be developed for further investigations [ 60 , 61 , 62 ]; for instance, one can study the levitation of a WLM by using a few FLMs in different directions facing each other. Low friction, low evaporation rate, and capability of rolling even on hydrophilic surfaces have made liquid marbles ideal for employment in lab-on-chip platforms, which could be utilized for biomedical and agricultural purposes.…”

Optimizing Optical Dielectrophoretic (ODEP) Performance: Position- and Size-Dependent Droplet Manipulation in an Open-Chamber Oil Medium

“…However, droplet-based microfluidics have difficulty, particularly in the manipulation of individual droplets driven by continuous oil flows confined in microfluidic channels. To address this, various active droplet manipulation mechanisms have been developed, including thermocapillary force [ 23 , 24 , 25 ], electrowetting on dielectric (EWOD) [ 26 , 27 , 28 ], dielectrophoresis (DEP) [ 29 , 30 , 31 ], acoustofluidic force [ 32 , 33 , 34 ], and contact charge electrophoresis (CCEP) [ 35 , 36 ]. Among these, DEP is notable for its low-cost, label-free approach, enabling particle manipulation through electric field non-uniformity without surface contact, thereby minimizing potential droplet–electrode contamination [ 37 , 38 , 39 ].…”

Controlled Transport of Individual Microparticles Using Dielectrophoresis

“…Manipulating microsized objects in a controlled way is of significant interest in many fields of science including biology, − medicine, and chemistry . This is especially relevant for designing micro total analysis systems (μTAS) where integrated microsample manipulation capabilities are highly desired. − Dielectrophoresis (DEP) is a powerful tool for such purposes as it allows nondestructive manipulation of colloidal objects/particles. It uses micro/nano-scale electrode arrays or patterned insulators to exert forces to move particles.…”