Interconnecting Microfluidic Package and Fabrication Method DIV

A one-piece, microfluidic package with standardized multiple ports allows devices to be connected in series without resorting to extra tubing connections or bonding 5 processes. The one-piece construction consists of microfluidic channels that can be connected to fluid reservoirs and other fluidic components fabricated with interconnecting and interlocking ports. The size of the friction-fit interlocking ports is designed such that the smaller male port fits snugly into the larger female port in a manner that is leak-free and adhesive-fiee. The friction-fit ports can also be 10 reconfigured. Thus, the interconnection of microfluidic packages can be in an extended series including connections to sensors and devices such as a bio/biochemical/chemical sensor chip, a dielectrophoretic manipulator chip, and a microfluidic reactor chip

Manipulation of Spherical Droplets on a Liquid Platform Using Thermal Gradients

In the recent years, there has been a growing interest in droplet-based (digital) microfluidics for which, reliable means of droplet manipulation are required. In this study we demonstrate thermal actuation of droplets on liquid platforms, which is ideal for biochemical microsystems and lab-on-chip applications because droplets can be transported with high speed, good control and minimal thermal loading as compared to using conventional solid substrates. In addition, other disadvantages of using solid surfaces such as evaporation, contamination, pinning, hysteresis and irreversibility of droplet motion are avoided. Based on the theoretical development and measurements, a silicon-based droplet transportation platform was developed with embedded Titanium micro heaters. A shallow liquid pool of inert liquid (FC-43) served as the carrier liquid. Heaters were interfaced with control electronics and driven through a computer graphical user interface. By creating appropriate spatio-temporal thermal gradient maps, transport of droplets on predetermined pathways was successfully demonstrated with high level of robustness, speed and reliability. The video shows normal imaging of droplet manipulation accompanied by the corresponding infrared thermal imaging showing the spatio-temporal temperature maps and the outline of the drop as it moves towards hot spots.Comment: 63rd APS - Division of Fluid Dynamics - 201

The Tec kinase ITK is required for homeostasis and anti-viral immune protection in the intestine

The Tec kinase ITK is activated by TCR stimulation and also required for TCR downstream signaling. Previous studies have reported differential roles of ITK and another Tec family kinase RLK in CD4+ TH differentiation and effector function. However, these findings are confounded by the complex T cell developmental defects in Itk-/- mice. Furthermore, the function of ITK in tissue-resident T cells in the intestine and anti-viral immune response to a persistent infection has not been studied previously. In addition to T cells, recent studies have indicated an expression of ITK in ILC2, but not in other ILC subsets. Yet, the role of ITK in ILC2 has not been characterized. Here, I have examined the role of ITK and RLK in CD4+ TH subsets using a small molecule inhibitor PRN694. I found that PRN694 impaired TH1 differentiation in vitro, and PRN694 administration prevented TH1-mediated colitis progression in vivo. In an MHV68 infection model, Itk-/- mice failed to control viral replication in the intestine, while gut-homing of CD8+ T cells was greatly impaired. Finally, I found that ILC2 number was markedly reduced in the intestine of Itk-/- mice. Gut-specific defect of Itk-/- ILC2 is associated with a low availability of IL-2 in the intestine of Itk-/- mice. Collectively, these data suggest that ITK is important in T cell migration to the intestine and ILC2 homeostasis in the intestine, thereby contributing to the protective response to a latent virus and intestinal tissue homeostasis

Micro integrated planar optical waveguide type SPR Sensor.

An integrated optical waveguide type surface plasmon resonance (SPR) sensor having an optical waveguide with a corresponding SPR sensing area, photodetectors, and wave-length tunable laser or any kind of external tunable laser source/coupler formed on a substrate. In an embodiment, the laser is a wavelength tunable laser and optionally, the integrated device may include a power source on the substrate for providing a electric power to the wavelength tunable laser and the photodetectors, or a circuit for signal processing, or a microfluidic structure for routing a target sample to the SPR sensor area. The microfluidic structure optionally includes a mixer or a reaction chamber for mixing and allowing a physical or chemical reaction to occur, respectively. In an embodiment, plural planar integrated optical waveguide type SPR sensors may be fabricated on a substrate to form a array of SPR sensors

Portable Water Quality Monitoring System

A disposable microsensor is designed, fabricated and tested for standard BOD (Biochemical Oxygen Demand) measurements. A transparent Cyclic Olefin Copolymer COC) substrate is used for sensor fabrication. Standard lithographic procedures in addition to techniques like screen printing and electroplating are used to fabricate the sensor. A microbial strain of Trichosporon Cutaneum is immobilized over one pair of sensor electrodes while the other is used as a reference. Depending on the respiratory activities of the microbial strain in different samples, the BOD values of the samples can be measured in terms of difference between the output signals. The sensor layer is attached to an injection-molded passive microfluidic channel on the top. Advantages of the BOD microsensor include, but are not limited to, fast BOD measurement, disposability because of its low cost, chemically inert polymer substrate, flow-through sample injection scheme and integration of on-chip optics

Portable Water Quality Sensor Fabrication Method

A disposable microsensor is designed, fabricated and tested for standard BOD (Biochemical Oxygen Demand) measurements. A transparent Cyclic Olefin Copolymer COC) substrate is used for sensor fabrication. Standard lithographic procedures in addition to techniques like screen printing and electroplating are used to fabricate the sensor. A microbial strain of Trichosporon Cutaneum is immobilized over one pair of sensor electrodes while the other is used as a reference. Depending on the respiratory activities of the microbial strain in different samples, the BOD values of the samples can be measured in terms of difference between the output signals. The sensor layer is attached to an injection-molded passive microfluidic channel on the top. Advantages of the BOD microsensor include, but are not limited to, fast BOD measurement, disposability because of its low cost, chemically inert polymer substrate, flow-through sample injection scheme and integration of on-chip optics

Microscale resin-bonded permanent magnets for magnetic micro-electro-mechanical systems applications

A micromachining technique has been developed for the fabrication of microscale resin-bonded permanent magnets. Magnetic paste has been prepared from Sr-ferrite powder and an epoxy resin, filled into lithographically defined molds, and formed into resin-bonded magnets after room temperature curing. Coercivity of 356 kA/m (4480 Oe), retentivity of 33 mT (330 G), and energy density of 2.7 kJ/m(3) have been achieved in 65-mum-thick disk arrays with lateral dimensions ranging from 50 to 200 mum. Based on the developed magnet, a magnetic MEMS actuator has been designed, fabricated, and characterized. Actuation current up to +/-60 mA operated the actuator up to 70 mum in attractive and repulsive motion. This work can be used for producing thick-film type permanent magnets, which can be scaled from a few tens of micrometers to millimeters on various substrates

Microfludic Mixer Having Channel Width Variation for Enhanced Fluid Mixing

A micromixing apparatus includes a mixing microchannel formed in a top surface of a substrate having channel length and a variable channel width defined by a first sidewall surface and a opposing second sidewall surface. The channel width varies from a minimum channel width h to a maximum channel width H in a ratio of H:h greater than or equal to 1.1:1.0. A first inlet is for injecting a first fluid into the mixing microchannel and a second inlet for injecting a second fluid into the mixing microchannel. The first and second fluid flow in a flow direction in the mixing microchannel along the channel length. The first sidewall surface includes first curved surface portions and the second sidewall surface includes a second curved surface portions. The plurality of first curved surface portions and plurality of second curved surface portions are non-overlapping to provide a variable channel width

Droplets on liquid surfaces: Dual equilibrium states and their energy barrier

Floating aqueous droplets were formed at oil-air interface, and two stable configurations of (i) non-coalescent droplet and (ii) cap/bead droplet were observed. General solutions for energy and force analysis were obtained for both configurations and were shown to be in good agreement with the experimental observations. The energy barrier obtained for transition from configuration (i) to configuration (ii) was correlated to the droplet release height and the probability of non-coalescent droplet formation

Adaptive laboratory evolution of a genome-reduced Escherichia coli.

Synthetic biology aims to design and construct bacterial genomes harboring the minimum number of genes required for self-replicable life. However, the genome-reduced bacteria often show impaired growth under laboratory conditions that cannot be understood based on the removed genes. The unexpected phenotypes highlight our limited understanding of bacterial genomes. Here, we deploy adaptive laboratory evolution (ALE) to re-optimize growth performance of a genome-reduced strain. The basis for suboptimal growth is the imbalanced metabolism that is rewired during ALE. The metabolic rewiring is globally orchestrated by mutations in rpoD altering promoter binding of RNA polymerase. Lastly, the evolved strain has no translational buffering capacity, enabling effective translation of abundant mRNAs. Multi-omic analysis of the evolved strain reveals transcriptome- and translatome-wide remodeling that orchestrate metabolism and growth. These results reveal that failure of prediction may not be associated with understanding individual genes, but rather from insufficient understanding of the strain's systems biology