Novel microfluidic chip can detect contaminants in 100-picoliter samples

Nanowerk  June 27, 2022 Researchers in Japan have developed a nonlinear optical crystal-based compact terahertz (THz)-microfluidic chip with several I-design meta-atoms for attomole (amol)-level sensing of trace amounts of solution samples. The chip consists of a metallic strip with a micrometer-sized gap sandwiched by other metallic strips. A point THz source locally generated by optical rectification at the irradiation spot of a femtosecond-pulse laser beam induced a tightly confined electric-field mode at the gap regions and modified the resonance frequency when a microchannel fabricated along the space between the metallic strips was filled with solutions. Using this chip, they could […]

Microparticles show ability to turn in reverse, paving the way for microfluidic devices

Nanowerk  February 23, 2022 Self-organized vortex of rotating microparticles in a fluid will reverse direction when an electric stimulus is interrupted and then reapplied with the same orientation. A team of researchers in the US (Argonne National Laboratory, Northwestern University) investigated how these collective self-assembled states can be controlled and manipulated, and what would happen when they stopped and then restarted the field fueling the motion of the particles. They found that the particles’ relative positions created a kind of distributed collective memory that caused them to begin to rotate in the opposite direction. They found that this phenomenon was […]

A path to new nanofluidic devices applying spintronics technology

Phys.org  July 2, 2020 Hydrodynamic motion can generate a flux of electron-spin’s angular momentum via the coupling between fluid rotation and electron spins resulting in spin hydrodynamic generation (SHDG). Researchers in Japan have demonstrated electric voltage generation due to the SHDG in a laminar flow of a liquid-metal mercury. They experimentally confirmed that in the laminar flow region, energy conversion efficiency was increased by approximately 100,000 times. The technique has applications in spintronics-based nanofluidic devices such as liquid metal flow, cooling mechanisms in fast breeder reactors or semiconductor devices, as well as application to flowmeters that electrically measure micro-flows…read more. […]

Sliding walls – a new paradigm for microfluidic devices

Nanowerk  April 9, 2020 Currently, fluidic control in microdevices is mainly achieved either by external pumps and valves, which are expensive and bulky, or by valves integrated in the chip. Researchers in France propose a new paradigm for actuation in microfluidic devices based on rigid or semi-rigid walls with transversal dimensions of hundreds of micrometres that can slide within a microfluidic chip and to intersect microchannels with hand-driven or translation stage-based actuation. The new concept for reconfigurable microfluidics, the implementation of a wide range of functionalities was facilitated and allowed for no or limited dead volume, low cost and low […]