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Generating, splitting, transporting, and merging droplets are fundamental and critical unit operations for digital (droplet-based) microfluidics. State-of-the-art digital microfluidics performs such operations commonly using electrowetting-on-dielectric (EWOD) in the typical configuration of two parallel channel plates. This paper presents such operations(More)
This paper presents how two-dimensional propulsion with steering capability is developed and realized for micro swimmers that may be used to navigate inside of human body. The propelling and steering forces are produced by oscillating multiple bubble columns, which are arranged in different directions on the micro swimmer. Since the resonant frequency of(More)
This paper describes an underwater micropropulsion principle where a gaseous bubble trapped in a suspended microchannel and oscillated by external acoustic excitation generates a propelling force. The propelling swimmer is designed and microfabricated from parylene on the microscale (the equivalent diameter of the cylindrical bubble is around 60 μm) using(More)
The Cheerios effect is a common phenomenon in which small floating objects are either attracted or repelled by the sidewall due to capillary interaction. This attractive or repulsive behavior is highly dependent on the slope angles (angles of the interface on the wall or floating object with respect to a horizontal line) that can be mainly controlled by the(More)
We report a novel concept and experimental proof to substantially augment gas exchange between liquid and gas in microfluidics. The key idea is to use an oscillating bubble array to generate microstreaming flows perpendicular to the main laminar liquid stream. As such, the laminar flow stream experiences substantially increased mixing and gas exchange(More)
This paper presents four droplet operations (creating, transporting, splitting and merging of droplets) actuated by dielectrowetting (not electrowetting), which fundamentally constitute a backbone of droplet-based digital microfluidics. These operations are successfully achieved for both non-conductive (dielectric) and conductive (DI water with/without(More)
This paper presents a new method to fabricate microtubes. The stress mismatch between two layers of a single (or different) material thin film is created by a mechanical stretcher. When the thin film is released from the substrate, it rolls up automatically to form the microtubes. Different types of materials are tested including magnesium, aluminum and(More)
This paper describes bi-directional (linear and rotational) propelling and 2-D steering of acoustic bubble-powered microswimmers that are achieved in a centimeter-scale pool (beyond chip level scale). The core structure of a microswimmer is a microtube with one end open in which a gaseous bubble is trapped. The swimmer is propelled by microstreaming flows(More)
In this work we present an image sensor with a 1280x960 array of 1.5μm GS pixels based on InVisage’s latest QuantumFilm. This image sensor, implemented in a standard 130nm technology, achieves over 40% QE at 940nm and was specifically designed for outdoor near infrared applications with active illumination such as face authentication and depth mapping. High(More)
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