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Johansson, Stefan
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Publications (10 of 39) Show all publications
Olsson, P., Nysjö, F., Carlbom, I. B. & Johansson, S. (2016). Comparison of walking and traveling-wave piezoelectric motors as actuators in kinesthetic haptic devices. IEEE Transactions on Haptics, 9(3), 427-431
Open this publication in new window or tab >>Comparison of walking and traveling-wave piezoelectric motors as actuators in kinesthetic haptic devices
2016 (English)In: IEEE Transactions on Haptics, ISSN 1939-1412, E-ISSN 2329-4051, Vol. 9, no 3, p. 427-431Article in journal (Refereed) Published
Abstract [en]

Piezoelectric motors offer an attractive alternative to electromagnetic actuators in portable haptic interfaces: they are compact, have a high force-to-volume ratio, and can operate with limited or no gearing. However, the choice of a piezoelectric motor type is not obvious due to differences in performance characteristics. We present our evaluation of two commercial, operationally different, piezoelectric motors acting as actuators in two kinesthetic haptic grippers, a walking quasi-static motor and a traveling wave ultrasonic motor. We evaluate each gripper's ability to display common virtual objects including springs, dampers, and rigid walls, and conclude that the walking quasi-static motor is superior at low velocities. However, for applications where high velocity is required, traveling wave ultrasonic motors are a better option.

National Category
Human Computer Interaction Robotics
Research subject
Computerized Image Processing; Engineering Science with specialization in Microsystems Technology
Identifiers
urn:nbn:se:uu:diva-262371 (URN)10.1109/TOH.2016.2537803 (DOI)000384670000012 ()27046907 (PubMedID)
Funder
Vårdal FoundationVINNOVA
Available from: 2016-03-30 Created: 2015-09-14 Last updated: 2018-01-11Bibliographically approved
Johansson, S. & Snis, N. (2014). An ultrasonic motor for high-precision positioning. In: : . Paper presented at Actuators 2014, Bremen, Germany (pp. 647-650). Bremen: Messe Bremen
Open this publication in new window or tab >>An ultrasonic motor for high-precision positioning
2014 (English)Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Bremen: Messe Bremen, 2014
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:uu:diva-284759 (URN)978-3-933339-22-5 (ISBN)
Conference
Actuators 2014, Bremen, Germany
Available from: 2016-04-19 Created: 2016-04-19 Last updated: 2016-04-26
Johansson, S. (2014). Micro- and Nanomanipulation for Nanomanufacturing. In: Bhushan, Bharat (Ed.), Encyclopedia of Nanotechnology: (pp. 1-17). springer
Open this publication in new window or tab >>Micro- and Nanomanipulation for Nanomanufacturing
2014 (English)In: Encyclopedia of Nanotechnology / [ed] Bhushan, Bharat, springer , 2014, p. 1-17Chapter in book (Refereed)
Place, publisher, year, edition, pages
springer, 2014
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-283464 (URN)10.1007/978-94-007-6178-0_100923-1 (DOI)978-94-007-6178-0 (ISBN)
Available from: 2016-04-13 Created: 2016-04-13 Last updated: 2016-04-19
Johansson, L., Evander, M., Lilliehorn, T., Almqvist, M., Nilsson, J., Laurell, T. & Johansson, S. (2013). Temperature and trapping characterization of an acoustic trap with miniaturized integrated transducers - towards in-trap temperature regulation. Ultrasonics, 53(5), 1020-1032
Open this publication in new window or tab >>Temperature and trapping characterization of an acoustic trap with miniaturized integrated transducers - towards in-trap temperature regulation
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2013 (English)In: Ultrasonics, ISSN 0041-624X, E-ISSN 1874-9968, Vol. 53, no 5, p. 1020-1032Article in journal (Refereed) Published
Abstract [en]

An acoustic trap with miniaturized integrated transducers (MITs) for applications in non-contact trapping of cells or particles in a microfluidic channel was characterized by measuring the temperature increase and trapping strength. The fluid temperature was measured by the fluorescent response of Rhodamine B in the microchannel. The trapping strength was measured by the area of a trapped particle cluster counter-balanced by the hydrodynamic force. One of the main objectives was to obtain quantitative values of the temperature in the fluidic channel to ensure safe handling of cells and proteins. Another objective was to evaluate the trapping-to-temperature efficiency for the trap as a function of drive frequency. Thirdly, trapping-to-temperature efficiency data enables identifying frequencies and voltage values to use for in-trap temperature regulation. It is envisioned that operation with only in-trap temperature regulation enables the realization of small, simple and fast temperature-controlled trap systems. The significance of potential gradients at the trap edges due to the finite size of the miniaturized transducers for the operation was emphasized and expressed analytically. The influence of the acoustic near field was evaluated in FEM-simulation and compared with a more ideal 1D standing wave. The working principle of the trap was examined by comparing measurements of impedance, temperature increase and trapping strength with impedance transfer calculations of fluid-reflector resonances and frequencies of high reflectance at the fluid-reflector boundary. The temperature increase was found to be moderate, 7 degrees C for a high trapping strength, at a fluid flow of 0.5 mm s(-1) for the optimal driving frequency. A fast temperature response with a fall time of 8 s and a rise time of 11 s was observed. The results emphasize the importance of selecting the proper drive frequency for long term handling of cells, as opposed to the more pragmatic way of selecting the frequency of the highest acoustic output. Trapping was demonstrated in a large interval between 9 and 11.5 MHz, while the main trapping peak displayed FWHM of 0.5 MHz. A large bandwidth enables a more robust manufacturing and operation while allowing the trapping platform to be used in applications where the fluid wavelength varies due to external variations in fluid temperature, density and pressure. 

Keywords
Acoustic trapping, Temperature analysis, Micro total analysis system, FEM simulation, Temperature regulation
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Microsystems Technology
Identifiers
urn:nbn:se:uu:diva-200031 (URN)10.1016/j.ultras.2013.01.010 (DOI)000317184400013 ()
Available from: 2013-05-23 Created: 2013-05-20 Last updated: 2017-12-06Bibliographically approved
Olsson, P., Johansson, S., Nysjö, F. & Carlbom, I. (2012). Rendering stiffness with a prototype haptic glove actuated by an integrated piezoelectric motor. In: Haptics: Perception, Devices, Mobility, and Communication: Part I. Paper presented at EuroHaptics 2012, Tampere, Finland, June 13-15 (pp. 361-372). Springer Berlin/Heidelberg
Open this publication in new window or tab >>Rendering stiffness with a prototype haptic glove actuated by an integrated piezoelectric motor
2012 (English)In: Haptics: Perception, Devices, Mobility, and Communication: Part I, Springer Berlin/Heidelberg, 2012, p. 361-372Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2012
Series
Lecture Notes in Computer Science ; 7282
National Category
Human Computer Interaction Interaction Technologies
Identifiers
urn:nbn:se:uu:diva-183878 (URN)10.1007/978-3-642-31401-8_33 (DOI)978-3-642-31400-1 (ISBN)
Conference
EuroHaptics 2012, Tampere, Finland, June 13-15
Projects
Whole Hand Haptics
Available from: 2012-05-30 Created: 2012-11-05 Last updated: 2018-01-12Bibliographically approved
Johansson, L., Enlund, J., Johansson, S., Katardjiev, I. & Yantchev, V. (2012). Surface acoustic wave induced particle manipulation in a PDMS channel: principle concepts for continuous flow applications. Biomedical microdevices (Print), 14(2), 279-289
Open this publication in new window or tab >>Surface acoustic wave induced particle manipulation in a PDMS channel: principle concepts for continuous flow applications
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2012 (English)In: Biomedical microdevices (Print), ISSN 1387-2176, E-ISSN 1572-8781, Vol. 14, no 2, p. 279-289Article in journal (Refereed) Published
Abstract [en]

A device for acoustic particle manipulation in the40 MHz range for continuous-flow operation in a 50 μm wide PDMS channel has been evaluated. Unidirectionalinterdigital transducers on a Y-cut Z-propagation lithiumniobate wafer were used to excite a surface acoustic wavethat generated an acoustic standing wave inside the microfluidicchannel. It was shown that particle alignment nodeswith different inter-node spacing could be obtained,depending on device design and driving frequency. Theobserved inter-node spacing differed from the standard halfwavelengthinter-node spacing generally employed in bulkacoustic transducer excited resonant systems. This effectand the related issue of acoustic node positions relative thechannel walls, which is fundamental for most continuousflow particle manipulation operations in channels, wasevaluated in measurements and simulations. Specificapplications of particle separation and alignment wherethese systems can offer benefits relative state-of the artdesigns were identified.

Keywords
Paricle Manipulatiom, Surface Acoustic Waves, Microwaves
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Science with specialization in Microsystems Technology; Engineering Science with specialization in Electronics
Identifiers
urn:nbn:se:uu:diva-162643 (URN)10.1007/s10544-011-9606-7 (DOI)000301544500004 ()
Projects
VR, "Thin Film Guided Microacoustic Waves in Periodical Systems: Theory and Applications "
Funder
Swedish Research Council, 2009-5056
Available from: 2011-12-02 Created: 2011-12-02 Last updated: 2017-12-08Bibliographically approved
Johansson, L., Enlund, J., Johansson, S., Katardjiev, I., Wiklund, M. & Yantchev, V. (2012). Surface acoustic wave-induced precise particle manipulation in a trapezoidal glass microfluidic channel. Journal of Micromechanics and Microengineering, 22(2), 025018
Open this publication in new window or tab >>Surface acoustic wave-induced precise particle manipulation in a trapezoidal glass microfluidic channel
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2012 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 22, no 2, p. 025018-Article in journal (Refereed) Published
Abstract [en]

Surface acoustic wave (SAW) excitation of an acoustic field in a trapezoidal glass microfluidic channel for particle manipulation in continuous flow has been demonstrated. A unidirectional interdigital transducer (IDT) on a Y-cut Z-propagation lithium niobate (LiNbO3) substrate was used to excite a surface acoustic wave at approximately 35 MHz. An SU8 layer was used for adhesive bonding of the superstrate glass layer and the substrate piezoelectric layer. This work extends the use of SAWs for acoustic manipulation to also include glass channels in addition to prior work with mainly poly-di-methyl-siloxane channels. Efficient alignment of 1.9 mu m polystyrene particles to narrow nodal regions was successfully demonstrated. In addition, particle alignment with only one IDT active was realized. A finite element method simulation was used to visualize the acoustic field generated in the channel and the possibility of 2D alignment into small nodal regions was demonstrated.

National Category
Engineering and Technology Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Science with specialization in Electronics; Engineering Science with specialization in Microsystems Technology
Identifiers
urn:nbn:se:uu:diva-169956 (URN)10.1088/0960-1317/22/2/025018 (DOI)000299959000018 ()
Funder
Swedish Research Council, 2009-5056
Available from: 2012-03-08 Created: 2012-03-07 Last updated: 2017-12-07Bibliographically approved
Olsson, P., Carlbom, I., Johansson, S. & Nysjö, F. (2011). Whole Hand Haptics. In: Medicinteknikdagarna Oktober 11-12 2011, Linköping, Sweden: . Paper presented at Medicinteknikdagarna Oktober 11-12 2011, Linköping, Sweden.
Open this publication in new window or tab >>Whole Hand Haptics
2011 (English)In: Medicinteknikdagarna Oktober 11-12 2011, Linköping, Sweden, 2011Conference paper, Published paper (Refereed)
Abstract [en]

Our sense of touch is in many ways the most sophisticated of our senses with receptors throughout the body. Unlike vision and hearing, haptics provides bi-directional communication between an individual and his/her environment. Yet, our sense of touch has been exploited for computer interfaces mostly in primitive ways, with both input and output limited to contact with a single point on a virtual object or to signal an event. But a single point of contact is often insufficient for exploration and manipulation: try to pick up a small object with only one finger! Current multi-point interaction devices are built using mechanical tendons, which are large and bulky and provide neither the stiffness nor the dynamic range required for object manipulation. We present a first generation of a haptic glove that acts as an external skeleton where the hand and finger joints are controlled by actuators that are integrated in the glove. This first prototype allows for six degrees of freedom (DOF) movement of the hand, and one DOF gripping with the thumb and index finger. The six DOF movements are accomplished with a commercial haptic arm, which allows us to simulate physical object properties such as weight, friction and inertia. The gripping force is controlled by the most compact high precision piezoelectric motor that is commercially available today, using a separate force sensor in a feed-back loop. The high stiffness of the motor in combination with a high dynamic speed range allows for delicate control of the gripping force. Combined with emerging 3D display technology, the haptic glove opens up exciting possibilities of co-located visio-haptic interaction more closely resembling real-world interaction.

Keywords
Haptics, Whole Hand
National Category
Engineering and Technology
Research subject
Computerized Image Processing; Engineering Science with specialization in Microsystems Technology
Identifiers
urn:nbn:se:uu:diva-164593 (URN)
Conference
Medicinteknikdagarna Oktober 11-12 2011, Linköping, Sweden
Projects
Whole Hand Haptics
Available from: 2011-12-21 Created: 2011-12-21 Last updated: 2016-04-20
Arbat, A., Edqvist, E., Casanova Mohr, R., Brufau, J., Canals, J., Samitier, J., . . . Dieguez, A. (2009). Design and validation of the control circuits for a micro-cantilever tool for a micro-robot. Sensors and Actuators A-Physical, 153(1), 76-83
Open this publication in new window or tab >>Design and validation of the control circuits for a micro-cantilever tool for a micro-robot
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2009 (English)In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 153, no 1, p. 76-83Article in journal (Refereed) Published
Abstract [en]

The objective of this paper is to present the design and validation of a cantilever-based contact sensing system for a micro-robot. Key elements of the fabrication process of the sensor and the electrical model extraction used to design the control electronics are described. The architecture used for the sensor corresponds to a micro-cantilever fabricated of piezoelectric-polyvinylidene fluoride-trifluoroethylene stacked in a multilayer structure with the possibility of both actuating and sensing. A lumped electro mechanical equivalent model of the micro-cantilever was used to design the control electronics for the cantilever. A driving signal from, the control system is used to vibrate the cantilever at its first mechanical resonance frequency. The control system contains an analog front-end to measure the sensor output signal and a digital control unit designed to track and keep the resonance frequency of the cantilever. By integrating the cantilever control system is integrated in the application specified integrated circuit used to control of the circuit is simplyfied and very compact. Experimental results show a similar behavior between the electrical model and the fabricated system, and the deviations between the model and the measured structure are analyzed. The results also show that the designed control system is capable to detect the resonance frequency of the system and to actuate despite small deviations in process parameters of different batches of cantilevers. The whole system was designed to be integrated into an autonomous micro-robot, although it can be used in other applications.

Place, publisher, year, edition, pages
P.O. Box 211, Amsterdam, 1000 AE, Netherlands: Elsevier, 2009
Keywords
Vibrating cantilever, Multilayer PVDF-TrFE sensor, Control electronics, Interface circuits
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-108493 (URN)10.1016/j.sna.2009.04.030 (DOI)000267646600012 ()09244247 (ISBN)
Note

Compilation and indexing terms, Copyright 2009 Elsevier Inc. 20092412122278 Analog front-end Contact sensing Control circuits Control electronics Digital control units Driving signal Electrical models Electro-mechanical Equivalent model Fabricated system Fabrication process In-process parameters Interface circuits Key elements Mechanical resonance frequency Micro robots Micro-cantilever Multilayer structures Other applications Polyvinylidene fluorides Resonance frequencies Sensor output Trifluoroethylene Vibrating cantilever Whole systems

Available from: 2009-09-20 Created: 2009-09-20 Last updated: 2017-12-13Bibliographically approved
Johansson, L., Johansson, S., Nikolajeff, F. & Thorslund, S. (2009). Effective mixing of laminar flows at a density interface by an integrated ultrasonic transducer. Lab on a Chip, 9(2), 297-304
Open this publication in new window or tab >>Effective mixing of laminar flows at a density interface by an integrated ultrasonic transducer
2009 (English)In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, no 2, p. 297-304Article in journal (Refereed) Published
Abstract [en]

An acoustic mixer for glass channel microfluidic systems is presented. An acoustic standing wave, perpendicular to the fluid flow, is generated by the excitation of a miniaturized piezoelectric transducer operated around 10 MHz. The transducer is fabricated into a planar printed circuit board structure, constituting the bottom channel wall, which makes the mixer simple to integrate with a wide selection of microfluidic channel designs. The mixing occurs at a fluid-fluid density interface due to the acoustic radiation force; an analytical expression is derived to qualitatively describe this phenomenon. Only a small density difference in the range of 2–5% is required to achieve 150–270% peak broadening of a fluorescent sample between sheath flows, which we use as a measure of the mixing efficiency. The mixing efficiency is measured with regard to its sensitivity to the density difference, the fluid velocity and the transducer driving frequency. Transducers at different positions along the microchannel make it possible to compare the mixing of straight versus diagonal flows across the transducer surface. We finally demonstrate enhanced chemical lysis of E. coli K12 cells in the device due to active fluid mixing.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-100676 (URN)10.1039/b815114h (DOI)000262649500017 ()
Available from: 2009-04-07 Created: 2009-04-05 Last updated: 2018-06-04Bibliographically approved
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