| 1. |
- Balslev, Soren, et al.
(författare)
-
Microfluidic dye laser with compact, low-cost liquid dye dispenser
- 2005
-
Ingår i: Micro Total Analysis Systems 2004. - 0854048960 ; , s. 375-377
-
Konferensbidrag (refereegranskat)abstract
- We present a compact system consisting of a miniaturized fluid dispenser, delivering liquid laser dye to a micro-chip dye laser. This demonstrates the elimination of bulk fluid pumps for a microfluidic system by using a miniaturized, electrically and chemically inert dispenser, capable of delivering very low flow for extended periods of time.
|
|
| 2. |
|
|
| 3. |
- Griss, Patrick, et al.
(författare)
-
Barbed spike arrays for mechanical chip attachment
- 2001
-
Ingår i: Proceedings of the IEEE Micro Electro Mechanical Systems. - 0780359984 ; , s. 46-49
-
Konferensbidrag (refereegranskat)abstract
- We fabricated and tested two types of microstructures for the mechanical attachment of chips to soft surfaces. The microstructures are barbed spikes etched in silicon using DRIE (Deep Reactive Ion Etching). The mechanical attachment of two types of barbed spike arrays was measured on nonbiological materials (Polyethylene foil, Aluminium foil and ParafilmTM) as well as on human skin. The maximum adhesion force was 1,36 N achieved by a 2×2 mm2 chip containing 64 barbed spikes pressed in Polyethylene foil. Maximum adhesion in skin was 0,54 N. The shape of the two different barb types has significant influence on the detachment forces for nonbiological materials
|
|
| 4. |
- Griss, Patrick, et al.
(författare)
-
Barbed Spikes for Mechanical Chip Attachment
- 2001
-
Ingår i: IEEE International Workshop on Micro Electromechanical Systems (MEMS2001), Interlaken, Switzerland, Jan. 21-25. ; , s. 46-49
-
Konferensbidrag (refereegranskat)
|
|
| 5. |
- Griss, Patrick, et al.
(författare)
-
Characterization of micromachined spiked biopotential electrodes
- 2002
-
Ingår i: IEEE Transactions on Biomedical Engineering. - 0018-9294 .- 1558-2531. ; 49:6, s. 597-604
-
Tidskriftsartikel (refereegranskat)abstract
- We present the characterization of dry spiked biopotential electrodes and test their suitability to be used in anesthesia monitoring systems based on the measurement of electroencephalographic signals. The spiked electrode consists of an array of microneedles penetrating the outer skin layers. We found a significant dependency of the electrode-skin-electrode impedance (ESEI) on the electrode size (i.e., the number of spikes) and the coating material of the spikes. Electrodes larger than 3 x 3 mm(2) coated with Ag-AgCl have sufficiently low ESEI to be well suited for electroencephalograph (EEG) recordings. The maximum measured ESEI was 4.24 kOmega and 87 kOmega, at 1 kHz and 0.6 Hz, respectively. The minimum ESEI was 0.65 kOmega an 16 kOmega, at the same frequencies. The ESEI of spiked electrodes is stable over an extended period of time. The arithmetic mean of the generated dc offset voltage is 11.8 mV immediately after application on the skin and 9.8 mV after 20-30 min. A spectral study of the generated potential difference revealed that the ac part was unstable at frequencies below approximately 0.8 Hz. Thus, the signal does not interfere with a number of clinical applications using real-time EEG. Comparing raw EEG recordings of the spiked electrode with commercial Zipprep electrodes showed that both signals were similar. Due to the mechanical strength of the silicon microneedles and the fact that neither skin preparation nor electrolytic gel is required, use of the spiked electrode is convenient. The spiked electrode is very comfortable for the patient.
|
|
| 6. |
- Griss, Patrick, et al.
(författare)
-
Micromachined barbed spikes for mechanical chip attachment
- 2002
-
Ingår i: Sensors and Actuators A-Physical. - 0924-4247 .- 1873-3069. ; 95:03-feb, s. 94-99
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the mechanical attachment of chips to surfaces capable of being penetrated by silicon spike,,. The attachment principle is inspired by fishhooks and arrows. Barbed spikes penetrate a material but offer resistance to detaching forces. Two types of barbed spikes were etched in silicon using deep reactive ion etching (DRIE). The mechanical attachment of both types of barbed spike arrays was measured on non-biological materials (polyethylene foil (PE), aluminium foil and Parafilm(TM)) as well as on human skin. The maximum adhesion force was 1.36 N achieved by a 2 x 2 mm(2) chip containing 64 barbed spikes, 160 mum in length, pressed into PE. Maximum adhesion in skin was 0.54 N. The shape of the two different barb types has significant influence on the detachment forces for non-biological materials.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Griss, Patrick, et al.
(författare)
-
Novel, side opened out-of-plane microneedles for microfluidic transdermal interfacing
- 2002
-
Ingår i: FIFTEENTH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS. - New York : IEEE. - 0780371852 ; , s. 467-470
-
Konferensbidrag (refereegranskat)abstract
- We present the first hollow out of wafer plane silicon microneedles that have openings in the shaft rather than having an orifice at the tip. These structures are 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 offering 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 needed. Using this chip in a typical application, e.g. vaccine delivery, a 100 mul volume of aqueous fluid injected through a chip of 30 mm(2) in 2s would cause a pressure drop of less than 2kPa. The presented needles are approximately 2 10 pm long.
|
|
| 10. |
- Griss, Patrick, et al.
(författare)
-
Side-opened out-of-plane microneedles for microfluidic transdermal liquid transfer
- 2003
-
Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 12:3, s. 296-301
-
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.
|
|
