University of Toronto

Sci-bots Inc.

Ryan Fobel

Aaron Ray Wheeler

Alphonsus Hon-Chung Ng

Christian Fobel

Andrea Kirby

Man Ho Stephen Ho

Man Ho Ho

Alphonsus Hon-Ghung Ng

Disclosed herein is a surfactant additive, ethylenediamine tetrakis(ethoxylate-block-propoxylate) tetrol with 16 ethylene oxide repeat units and 18 propylene oxide repeat units (known by its trade name as Tetronic 90R4) used as a droplet-additive, or to coat DMF driving electrode surfaces which dramatically improves the capability to work with high-protein-content liquids (e.g., whole blood) on digital microfluidic chips. This surfactant prevents protein adsorption and fouling of DMF electrode surfaces to an extent that was heretofore impossible. Specifically, this surfactant allows for the manipulation of droplets of undiluted whole blood for &#x3e;1 hour per electrode (&#x3e;1 50 times better than what is possible for any known additive). This improvement in handling high protein content media will revolutionize blood-based diagnostics on digital microfluidic platforms.

Surfactant additives for digital microfluidic devices for high protein content droplets transport

The present disclosure discloses a multi-droplet sensing and actuation system, for use in a digital microfluidic chip operation wherein a linearly independent alternating current signal is applied to each discrete actuation electrode thus encoding the electrode's identity. The combined measured impedance signal from multiple channels is then processed to decode an impedance measurement for the volume between each discrete actuation electrode and its corresponding conductive counter electrode region, where the sensed impedance is inversely proportional to an amount of liquid within the volume.

Multiplexed droplet actuation and sensing in digital microfluidics

Embodiments of the present disclosure digital microfluidic arrays that may be fabricated by a printing method, whereby digital microfluidic electrodes arrays are printed, via a printing method such as inkjet printing, onto a suitable substrate. In some embodiments, a substrate and/or ink is prepared or modified to support the printing of electrode arrays, such as via changes to the surface energy. In some embodiments, porous and/or fibrous substrates are prepared by the addition of a barrier layer, or, for example, by the addition or infiltration of a suitable material to render the surface capable of supporting printed electrodes. Various example embodiments involving hybrid devices formed by the printing of digital microfluidic arrays onto a substrate having a hydrophilic layer are disclosed.

Printed digital microfluidic devices methods of use and manufacture thereof

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Toronto, Canada

Ryan Fobel