Glennys A. Mensing

An externally driven magnetic microstirrer

In this paper, an inexpensive, easy–to–fabricate active magnetic mixer is presented. This mixer functions on top of a common magnetic stir plate and is capable of mixing two streams, each at flow rates up to 5 ml min–1. A liquid–phase photopolymerization technique is used to fabricate the device. An analysis of mixing efficiency is based on greyscale intensity measurements of two coloured streams passing through the mixer. A brief hypothesis of the mechanism of mixing is also presented.

Ultra rapid prototyping of microfluidic systems using liquid phase photopolymerization

We present a method for the ultra rapid prototyping of microfluidic systems using liquid phase photopolymerization, requiring less than 5 min from design to prototype. Microfluidic device fabrication is demonstrated in a universal plastic or glass cartridge. The method consists of the following steps: introduction of liquid prepolymer into the cartridge, UV exposure through a mask to define the channel geometry, removal of unpolymerized prepolymer, and a final rinse. Rapidly fabricated masters for polydimethylsiloxane micromolding are also demonstrated. The master making process is compared to SU-8 50 photoresist processes. Press-on connectors are developed and demonstrated. All materials used are commercially available and low cost. An extension of these methods (mix and match) is presented that allows for maximal design flexibility and integration with a variety of existing fluidic geometries, components, and processes.

Alternative Approaches to Microfluidic Systems Design, Construction and Operation

An alternative approach (µFluidic Tectonics) to microfluidic device construction that utilizes liquid phase photopolymerization and responsive materials is presented. Ultra rapid (3 min) microchannel fabrication is demonstrated. Filtering, flow control, and mixing components are demonstrated.

An in-plane active magnetic mixer for microfluidic applications

We report the properties of a magnetically actuated mixing and blending device that is fabricated using microfluidic tectonics methods. A small metal blade is confined within a microfluidic channel. A post is polymerized through a hole in the blade to hold it in place and allow it to spin freely when a common magnetic stirrer is activated. The moving blade allows fluid streams to mix. The blade can also be used to break up biological materials inside a microchannel.

An Ultrarapid Method of Creating 3D Channels and Microstructures

We present a method of creating three dimensional microfluidic channel networks and freestanding microstructures using liquid phase photopolymerization techniques. The use of liquid phase microfabrication facilitates the creation of microstructured devices using low-cost materials and equipment. The ability to add multiple layers allows for complex geometries and increases the functional density of channeled devices. The multilayer technique provides a method of interconnecting layers or combining separate layers to form a truly integrated multilayered microfluidic device, as well as a means of forming multilayered freestanding structures. Because this method is based on the fundamentals of microfluidic tectonics (μFT), all components (valves, mixers, filters) compatible with μFT can be integrated into the multilayer channel networks.

Liquid Phase 3D Channel Networks

A method of creating a multilayer device using liquid phase photopolymerization techniques is presented. A multilayer device has been demonstrated that has interconnected and separate layers. The method is used to create a 3D serpentine micromixer positioned around a central channel.