Tilted Micro Air Jet for Flow Control

In this paper, we present an interesting method to microfabricate a tilted micro air jet generator. We used the well-know deep reactive ion etching (DRIE) technique in order to realize in a silicon substrate a double side etching. For aircraft and cars, micro air jets will take an important place for fluid control. Micro air jets are characterized by their speed, frequency and tilt. Usually, this micro air jets are produced by fluidic microsystems. We presented experimental results about micro tilted air jets. A comparison between finite element method simulation, theory and experimental results are performed to define the microsystem geometry leading a specific air jet angle

5-oxoETE triggers nociception in constipation-predominant irritable bowel syndrome through MAS-related G protein-coupled receptor D.

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that is characterized by chronic abdominal pain concurrent with altered bowel habit. Polyunsaturated fatty acid (PUFA) metabolites are increased in abundance in IBS and are implicated in the alteration of sensation to mechanical stimuli, which is defined as visceral hypersensitivity. We sought to quantify PUFA metabolites in patients with IBS and evaluate their role in pain. Quantification of PUFA metabolites by mass spectrometry in colonic biopsies showed an increased abundance of 5-oxoeicosatetraenoic acid (5-oxoETE) only in biopsies taken from patients with IBS with predominant constipation (IBS-C). Local administration of 5-oxoETE to mice induced somatic and visceral hypersensitivity to mechanical stimuli without causing tissue inflammation. We found that 5-oxoETE directly acted on both human and mouse sensory neurons as shown by lumbar splanchnic nerve recordings and Ca2+ imaging of dorsal root ganglion (DRG) neurons. We showed that 5-oxoETE selectively stimulated nonpeptidergic, isolectin B4 (IB4)-positive DRG neurons through a phospholipase C (PLC)- and pertussis toxin-dependent mechanism, suggesting that the effect was mediated by a G protein-coupled receptor (GPCR). The MAS-related GPCR D (Mrgprd) was found in mouse colonic DRG afferents and was identified as being implicated in the noxious effects of 5-oxoETE. Together, these data suggest that 5-oxoETE, a potential biomarker of IBS-C, induces somatic and visceral hyperalgesia without inflammation in an Mrgprd-dependent manner. Thus, 5-oxoETE may play a pivotal role in the abdominal pain associated with IBS-C.BBSRC BB/R006210/1 to James R F Hockley and Ewan St John Smith Rosetrees 834 Postdoctoral Grant (A1296) awarded to James R F Hockley and Ewan St John Smit

Conception et réalisation d'un micro-actionneur électrostatique pour le contrôle de la couche limite

International audienc

A New Two-Dimensional Actuator for Air Flow Micro-manipulation

International audienceA two dimensional pneumatic actuator based on silicon MEMS technology for objects micro-manipulation is presented. The device uses inclined air jets to levitate and convey micro-objects to the desired position. The structure consists of a sandwich of silicon-silicon-Pyrex layers fabricated using MEMS technologies such as deep reactive ion etching (DRIE) and ultrasonic micro-machining techniques. A two dimensional system composed of 64 micro-conveyors in about 9mm x 9 mm area was realized. Each micro-conveyor has four nozzles and can generate inclined air-jets which allow four conveyance directions. Two-dimensional conveyance of a silicon chip of 3 mm diameter and weighing approximately 2mg was performed with pulsed air flow of 20 kPa

A MEMS-based pneumatic micro-conveyor for planar micromanipulation

7 pagesInternational audienceThis paper present a two dimensional pneumatic actuator based on silicon MEMS technology for objects micro-manipulation using tilted air jets. The device is composed of three layers stacked together, two micro-machined silicon wafers and a Pyrex glass wafer. The system is composed of a set of micro-conveyors in about 9 mm x 9 mm area. Each micro-conveyor has four nozzles and can generate tilted air-jets which allow four conveyance directions. An experiment of the conveyance of a silicon chip of 3 mmdiameter and weighing approximately 2 mg was performed with pulsed air flow

Design and fabrication of a new two-dimensional pneumatic micro-conveyor

International audienceThis paper presents the design, fabrication and testing of a new two-dimensional pneumatic conveyor for micro-chips manipulation. The conveyor can levitate and move flat objects to a desired position using controlled air-flow. The structure consists of a sandwich of silicon–silicon–Pyrex layers fabricated using MEMS technologies, in which deep reactive ion etching (DRIE) and ultrasonic micro-machining techniques were used for the fabrication of silicon and Pyrex chips, respectively. The silicon–silicon wafers and silicon–Pyrex wafers were bonded by gold eutectic bonding and anodic bonding techniques, respectively. The device array is about 9 mm × 9 mm of surface dimension and composed of 8 × 8 pneumatic micro-conveyors. A micro-conveyor has four nozzles that can generate inclined air-jets allowing four conveyance directions. We demonstrate experimentally that a 3 mm diameter object of 2 mg weight can be conveyed to a desired position with intermittent air-flow of 20 kPa

CMOS Post-Processing of Ciliary Motion Actuators of UV-patterned Polyimides

International audienceThe fabrication of a ciliary motion system (CMS) has been successfully achieved using photosensitive polyimides patterned by a direct UV lithography technique. The characteristics of the device are equivalent to those of the previous devices made by classical methods, including plasma ashing. Process of micro-fabrication has also been enhanced