A microfluidic system includes a fluidic platform having a surface, a first liquid disposed onto the fluidic platform, and a droplet disposed onto the first liquid. The first liquid has a first temperature. The droplet has a second temperature higher than the first temperature so that the droplet is levitated above the first liquid by a cushion of vapor of the first liquid. In an embodiment, a device is configured to provide a magnetic field that has variable strength across the surface. A location of a magnetic droplet relative to the surface area is affected by the magnetic field. A method includes providing a fluidic platform, providing a magnetic field, introducing a first liquid onto the fluidic platform, introducing a first magnetic droplet onto the first liquid, and locally varying the magnetic field.

A single junction sorter for a microfluidic particle sorter, the single-junction sorter comprising: an input channel, configured to receive a fluid containing particles; an output sort channel and an output waste channel, each connected to the input channel for receiving the fluid therefrom; a bubble generator, operable to selectively displace the fluid around a particle to be sorted and thereby to create a transient flow of the fluid in the input channel; and a vortex element, configured to cause a vortex in the transient flow in order to direct the particle to be sorted into the output sort channel.

A single junction sorter for a microfluidic particle sorter, the single-junction sorter comprising: an input channel, configured to receive a fluid containing particles; an output sort channel and an output waste channel, each connected to the input channel for receiving the fluid therefrom; a bubble generator, operable to selectively displace the fluid around a particle to be sorted and thereby to create a transient flow of the fluid in the input channel; and a vortex element, configured to cause a vortex in the transient flow in order to direct the particle to be sorted into the output sort channel.

Air-matrix digital microfluidics (DMF) apparatuses and methods of using them to prevent or limit evaporation and surface fouling of the DMF apparatus. In particular, described herein are air-matrix DMF apparatuses and methods of using them including thermally controllable regions with a wax material that may be used to selectively encapsulate a reaction droplet in the air gap of the apparatus; additional aqueous droplets may be combined with the encapsulated droplet even after separating from the wax, despite residual wax coating, by merging with an aqueous droplet having a coating of a secondary material (e.g., an oil or other hydrophobic material) that may remove the wax from the droplet and/or allow combining of the droplets.

Methods described herein provide a way to reduce or eliminate drag and adhesion of a substance flowing over a surface by creating a vapor cushion via evaporation of a phase-changing material of or on the surface or encapsulated within textures of the surface. The vapor cushion causes the flowing substance to be suspended over the surface, greatly reducing friction, drag, and adhesion between the flowing substance and the surface. The temperature of the flowing substance is above the sublimation point and/or melting point of the phase-changing material. The phase-changing material undergoes a phase change (evaporation or sublimation) upon contact with the flowing substance due to local heat transfer from the flowing substance to the material, generating a vapor cushion between the solid or liquid material and the flowing substance.

Disclosed herein are devices, systems, and methods for sorting a particle based on a characteristic of a particle.

This invention discloses methods for producing modified cellulose, modified nanocellulose, modified nanocellulose functionalized with other functional species, and derivatives thereof. The present invention also provides cellulose, nanocellulose, and their derivatives that are safe to use inside an animal or human body and are biocompatible without costly purification. These cellulose or nanocellulose materials can be used in many different applications, including carrier for pharmaceutical active agents and other medical devices.

A microfluidic device includes a first substrate and a second substrate opposite to each other. A light-emitting layer, a first driving layer, and a first hydrophobic layer are on surface of the first substrate facing the second substrate; and first hydrophobic layer is disposed near second substrate; a photosensitive layer, a second driving layer and a second hydrophobic layer are on surface of the second substrate facing the first substrate; and second hydrophobic layer is disposed near first hydrophobic layer, and a gap for holding a droplet is between second hydrophobic layer and first hydrophobic layer; the first and second driving layers are configured to drive the droplet to move within the gap when applied with a driving voltage; the light-emitting layer is configured to emit light with a set wavelength toward the gap; and the photosensitive layer is configured to generate an induced current according to received light.

Systems and methods are provided for high-efficiency transport of single particles for inductively coupled plasma mass spectrometry. Single particles may be delivered to the mass spectrometer for quantification of trace elements. The systems may include droplet generation, conveyance module, capillary tubing, and/or an integrated inductively coupled plasma (ICP) torch, which may allow for the sequential transportation of single particles.

Air-matrix digital microfluidics (DMF) apparatuses and methods of using them to prevent or limit evaporation and surface fouling of the DMF apparatus. In particular, described herein are air-matrix DMF apparatuses and methods of using them including thermally controllable regions with a wax material that may be used to selectively encapsulate a reaction droplet in the air gap of the apparatus; additional aqueous droplets may be combined with the encapsulated droplet even after separating from the wax, despite residual wax coating, by merging with an aqueous droplet having a coating of a secondary material (e.g., an oil or other hydrophobic material) that may remove the wax from the droplet and/or allow combining of the droplets.