International Business Machines Corporation

Christian Michael Schwemmer

Armin W Knoll

Michael Skaug

Stefan Fringes

Colin Rawlings

Francesca Ruggeri

Darius Urbonas

Thilo Hermann Curt Stoeferle

A microfluidic device includes: a microchannel defining a flow path; a Brownian motor structure comprising two or more sorting channels having distinct ratchet topographies, the Brownian motor structure in fluid communication with the microchannel; and a filter extending transversely to the microchannel, the filter configured to filter particles, subject to sizes thereof, in a liquid advancing along the flow path, whereby smaller particles of the liquid can pass downstream of the filter in the flow path, and larger particles of the liquid are directed to the Brownian motor structure to be sorted out according to sizes thereof via the sorting channels.

Up-concentration and size sorting of nanoparticles in microfluidic devices

A detection device can include a cavity structure forming a Fabry-Perot optical microcavity, an electrostatic trap, and a Brownian motor. The Fabry-Perot optical microcavity has two mirrors extending on each side of a reference plane in a spacer region between the two mirrors. The mirrors are configured to vertically confine radiation in the spacer region, e.g., with respect to a first direction perpendicular to the reference plane. The electrostatic trap is arranged in the spacer region. The trap includes a pit and the cavity structure is generally configured to confine radiation in the pit, laterally (e.g., with respect to a second direction parallel to the reference plane). The Brownian motor structure extends in the spacer region along said reference plane. This structure is adapted to laterally load particles in the pit of the electrostatic trap by moving such particles along the structure, in operation.

Optical microcavities with integrated electrostatic confinement and brownian motors

Embodiments of the invention include a microfluidic device, which comprises a substrate with a channel defined therein, on an upper surface of the substrate, wherein a bottom wall of the channel comprises several contiguous steps having an asymmetric profile along a main direction of the channel, so as to form a ratchet topography. The device further comprises a lid, opposite to and at a distance from the upper surface of the substrate, so as to face the bottom wall of the channel. The bottom wall and the lid are designed to allow like sign charges to accumulate thereat, in presence of a polar liquid confined in the channel between the bottom wall and the lid, so as to allow displacement of nanoscale particles in the polar liquid, along said main direction of the channel, under application of an alternating force to said nanoscale particles, in operation of the device.

Microfluidic ratchets for displacing particles

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Zurich, Switzerland

Christian Michael Schwemmer