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Schweitz, Jan-Åke
Alternative names
Publications (10 of 22) Show all publications
Bodén, R., Hjort, K., Schweitz, J.-Å. & Simu, U. (2008). A metallic micropump for high-pressure microfluidics. Journal of Micromechanics and Microengineering, 18(11), 115009
Open this publication in new window or tab >>A metallic micropump for high-pressure microfluidics
2008 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 18, no 11, p. 115009-Article in journal (Refereed) Published
Abstract [en]

This paper presents one of the strongest mechanical sub-cm(3) sized micropumps for microfluidics. It consists of two active valves and one pumping chamber, each operated by a paraffin actuator that is driven by a low-voltage square pulse waveform. The pump is fabricated in a simple process using parylene-coated stainless steel stencils, paraffin and copper clad polyimide. When driving the pump at 0.07 Hz and 2.0 V (0.8 W) per actuator, it pumped water without leakage at a flow rate of 0.75 mu L min(-1) up to above 50 bar (5 MPa) back-pressure. The frequency dependence was evaluated and a maximum flow rate of 1 mu L min(-1) at 0.21 Hz and 1.8 V was observed. A thermomechanical FEM analysis, which was in good agreement with experiments at low frequencies, predicts the behaviour at higher frequencies.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-97829 (URN)10.1088/0960-1317/18/11/115009 (DOI)000260263900009 ()
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2017-12-14
Lehto, M., Bodén, R., Simu, U., Hjort, K., Thornell, G. & Schweitz, J.-Å. (2008). A polymeric paraffin microactuator. Journal of microelectromechanical systems, 17(5), 1172-1177
Open this publication in new window or tab >>A polymeric paraffin microactuator
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2008 (English)In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 17, no 5, p. 1172-1177Article in journal (Refereed) Published
Abstract [en]

Paraffin wax is a promising material in microactuators not only because of its ability of producing large displacements and high forces at the same time but also because of the variety of manufacturing techniques available. In this paper, a simple actuator based on paraffin wax as the active material is fabricated and tested. Ultraviolet-curable epoxy is used in a technique combining simultaneous moulding and liquid-phase photopolymerization in a single-process step to build the stiff part of the actuator body. A heater is integrated in the paraffin reservoir, and a polyimide tape is used as the deflecting membrane. Thermornechanical analysis of the paraffin wax shows that it exhibits a volume expansion of 10%, including phase transitions and linear expansion. As for the actuator, a stroke of 90 mu m is obtained for the unloaded device, whereas 37 mu m is recorded with a 0.5-N contact load at a driving voltage of 0.71 V and a frequency of 1/32 Hz. The actuator can be used in microsystems, where both large strokes and forces are needed. The low-cost materials and low driving voltage also makes it suitable for disposable systems.

Keywords
Actuator, paraffin wax, rapid prototyping
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-97825 (URN)10.1109/JMEMS.2008.927034 (DOI)000260464800012 ()
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2017-12-14
Bodén, R., Hjort, K., Simu, U. & Schweitz, J.-Å. (2008). Metallic high-pressure microfluidic pump. In: MSW08: . Paper presented at Micro System Workshop (pp. 29).
Open this publication in new window or tab >>Metallic high-pressure microfluidic pump
2008 (English)In: MSW08, 2008, p. 29-Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-111690 (URN)
Conference
Micro System Workshop
Available from: 2009-12-21 Created: 2009-12-21 Last updated: 2016-04-12Bibliographically approved
Bodén, R., Lehto, M., Margell, J., Hjort, K. & Schweitz, J.-Å. (2008). On-chip liquid storage and dispensing for lab-on-a-chip applications. Journal of Micromechanics and Microengineering, 18(7), 075036
Open this publication in new window or tab >>On-chip liquid storage and dispensing for lab-on-a-chip applications
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2008 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 18, no 7, p. 075036-Article in journal (Refereed) Published
Abstract [en]

This work presents novel components for on-chip storage and dispensing inside a lab-on-a-chip (LOC) for applications in immunoassay point-of-care testing (POCT), where incubation and washing steps are essential. It involves easy-to-use on-chip solutions for the sequential thermo-hydraulic actuation of liquids. The novel concept of combining the use of a rubber plug, both as a non-return valve cap and as a liquid injection interface of a sealed reservoir, allows simple filling of a sterilized cavity, as well as the storage and dispensing of reagent and washing buffer liquids. Segmenting the flow with air spacers enables effective rinsing and the use of small volumes of on-chip stored liquids. The chip uses low-resistance resistors as heaters in the paraffin actuator, providing the low-voltage actuation that is preferred for handheld battery driven instruments.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-97831 (URN)10.1088/0960-1317/18/7/075036 (DOI)000257128100037 ()
Available from: 2008-11-18 Created: 2008-11-18 Last updated: 2017-12-14
Lehto, M., Bodén, R., Simu, U., Hjort, K., Thornell, G. & Schweitz, J.-Å. (2008). Rapid prototyping of a polymeric paraffin microactuator. Journal of microelectromechanical systems, 17(5), 1172-1177
Open this publication in new window or tab >>Rapid prototyping of a polymeric paraffin microactuator
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2008 (English)In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 17, no 5, p. 1172-1177Article in journal (Refereed) Published
Abstract [en]

Paraffin wax is a promising material in microactuators not only because of its ability of producing large displacements and high forces at the same time but also because of the variety of manufacturing techniques available. In this paper, a simple actuator based on paraffin wax as the active material is fabricated and tested. Ultraviolet-curable epoxy is used in a technique combining simultaneous moulding and liquid-phase photopolymerization in a single-process step to build the stiff part of the actuator body. A heater is integrated in the paraffin reservoir, and a polyimide tape is used as the deflecting membrane. Thermomechanical analysis of the paraffin wax shows that it exhibits a volume expansion of 10%, including phase transitions and linear expansion. As for the actuator, a stroke of 90 mum is obtained for the unloaded device, whereas 37 mum is recorded with a 0.5-N contact load at a driving voltage of 0.71 V and a frequency of 1/32 Hz. The actuator can be used in microsystems, where both large strokes and forces are needed. The low-cost materials and low driving voltage also makes it suitable for disposable systems.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-96074 (URN)10.1109/JMEMS.2008.927034 (DOI)000260464800012 ()
Available from: 2007-09-03 Created: 2007-09-03 Last updated: 2017-12-14Bibliographically approved
Lehto, M., Schweitz, J.-Å. & Thornell, G. (2007). Binary mixtures of n-alkanes for tunable thermohydraulic microactuators. Journal of microelectromechanical systems, 16(3), 728-733
Open this publication in new window or tab >>Binary mixtures of n-alkanes for tunable thermohydraulic microactuators
2007 (English)In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 16, no 3, p. 728-733Article in journal (Refereed) Published
Abstract [en]

The two objectives of this paper are related to the use of n-alkanes in actuators. The first objective is to study the thermomechanics of binary mixtures of dotriacontane and hexatriacontane to see if a quasi-stable thermal expansion can be obtained, and the second one is to find the correspondence between dilatometry [pressure, volume, and temperature (pVT) measurement] and differential scanning calorimetry (DSC). Results show that there is indeed a concentration-dependent plateau in the expansion curves and that the width and horizontal position of this can be adjusted. As compared with pure n-alkanes, the plateaus of the mixtures widen by a factor of 2-4, and as compared with pure hexatriacontane, they shift their low-end temperatures by 5 °C to 10 °C, in the 25% to 75% concentration range. The mixtures' plateaus (gathered around 0.06 cm3/g) are about 0.02 cm3/g below those of the pure n-alkanes. It is shown that DSC can be used for a prediction of the thermomechanical properties of the substances, provided that a pVT reference exists, and the fact that the melting point increases with the pressure that is experienced with the dilatometer is considered. The qualitative similarity between the expansion and enthalpy curves is remarkable. About 25% to 30% of the total volume expansion is attributed to the solid-to-solid phase transition; the rest is attributed to thermal expansion and melting.

Keywords
Finite element method, Modelling, Similarity solution, Paraffin wax, Phase transformations, Low temperature, Calorimetry, Thermal expansion, Temperature measurement, Thermomechanical properties, Actuators, Microactuators, Microelectromechanical device
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-96073 (URN)10.1109/JMEMS.2007.893516 (DOI)000247219200027 ()
Available from: 2007-09-03 Created: 2007-09-03 Last updated: 2017-12-14Bibliographically approved
Boden, R., Simu, U., Margell, J., Lehto, M., Hjort, K., Thornell, G. & Schweitz, J.-Å. (2007). Metallic high-pressure microfluidicpump with active valves. In: : . Paper presented at 14th int. Conf. on Solid-State Sensors, Actuators and Microsystems, Transducers 2007, Lyon, France june 10-14.
Open this publication in new window or tab >>Metallic high-pressure microfluidicpump with active valves
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2007 (English)Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-13479 (URN)
Conference
14th int. Conf. on Solid-State Sensors, Actuators and Microsystems, Transducers 2007, Lyon, France june 10-14
Available from: 2008-01-23 Created: 2008-01-23 Last updated: 2016-04-11
Valizadeh, S., Abid, M., Romano-Rodriguez, A., Hjort, K. & Schweitz, J.-Å. (2006). Electrical contacting of individual electrodeposited Au Nanowire by Focused Ion Beam techniques. Nanotechnology, 1134-1139
Open this publication in new window or tab >>Electrical contacting of individual electrodeposited Au Nanowire by Focused Ion Beam techniques
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2006 (English)In: Nanotechnology, p. 1134-1139Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-22377 (URN)
Available from: 2007-04-24 Created: 2007-04-24 Last updated: 2016-07-12
Valizadeh, S. & Schweitz, J. Å. (2006). Nanoscale Electrical Transport Measurements by Focused Ion Beam. In: : . Paper presented at Scandem.
Open this publication in new window or tab >>Nanoscale Electrical Transport Measurements by Focused Ion Beam
2006 (English)Conference paper, Published paper (Refereed)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-26294 (URN)
Conference
Scandem
Available from: 2007-04-24 Created: 2007-04-24 Last updated: 2016-07-12
Valizadeh, S. & Schweitz, J. Å. (2006). Nanoscale Electrical Transport Measurements by Focused Ion Beam. SPIE NEWS ROOM
Open this publication in new window or tab >>Nanoscale Electrical Transport Measurements by Focused Ion Beam
2006 (English)In: SPIE NEWS ROOMArticle in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-26548 (URN)
Available from: 2007-02-20 Created: 2007-02-20 Last updated: 2016-07-12
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