| 1. |
- Griss, Patrick, et al.
(författare)
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Side-opened out-of-plane microneedles for microfluidic transdermal liquid transfer
- 2003
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Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 12:3, s. 296-301
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Tidskriftsartikel (refereegranskat)abstract
- We present the first hollow out-of-wafer-plane silicon microneedles having openings in the shaft rather than having an orifice at the tip. These structures are well suited for transdermal microfluidic applications, e.g., drug or vaccine delivery. The developed deep-reactive ion etching (DRIE) process allows fabrication of two dimensional, mechanically highly resistant needle arrays offering low resistance to liquid flows and a large exposure area between the fluid and the tissue. The presented process does not require much wafer handling and only two photolithography steps are required. Using a 3 x 3 mm(2) chip in a typical application, e.g., vaccine delivery, a 100 mul volume of aqueous fluid injected in 2 s would cause a pressure drop of less than 2 kPa. The presented needles are approximately 210 mum long.
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| 2. |
- Melin, Jessica, et al.
(författare)
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A LIQUID-TRIGGERED LIQUID MICROVALVE
- 2003
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Ingår i: 12th IEEE International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCERS 2003). - NEW YORK : IEEE conference proceedings. - 0780377311 ; , s. 1562-1565
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Konferensbidrag (refereegranskat)abstract
- This work introduces a novel surface tension and geometry based liquid-triggered liquid microvalve for on-chip liquid control. The simultaneous presence of two liquid plugs at the uncomplicated valve junction triggers the further movement of the liquids and overcomes the stop valve function of the device, thereby providing a precise means of timing liquid movement on-chip. The structure was shown to successfully function and forms the basis for several novel and useful functions, including fluidic AND gates, contactless on-chip liquid sample control, timing of independent processes on the same microchip, bubble-free joining of liquids, all of which pose great challenges in the area of microfluidics.
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| 3. |
- Samel, Björn, et al.
(författare)
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Expandable microspheres incorporated in a PDMS matrix : A novel thermal composite actuator for liquid handling in microfluidic applications
- 2003
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Ingår i: BOSTON TRANSDUCERS'03. - NEW YORK : IEEE. - 0780377311 ; , s. 1558-1561
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Konferensbidrag (refereegranskat)abstract
- In this study a novel actuator concept based on expandable microspheres incorporated in a PDMS matrix is presented. Merging the merits of the two substances gives the resulting composite material novel application possibilities as well as novel performance and processing properties. The expansion behavior of the composite was investigated and a maximum volume change of 270% of its original volume was measured after heating to 80degreesC. Applying a heat treatment to the composite shows its capability of filling out deep voids. The composite shows very good applicability as embedded actuator and may be appropriate for various applications. Furthermore, the applicability of the composite for replica molding has been demonstrated by creating inverse replicated features in the cured composite. We show the investigation of fabrication, expansion and application techniques by means of a novel actuator concept for liquid handling.
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