Cell and Particle Trapping in Microfluidic Systems Using Ultrasonic Standing Waves
Författare
Summary, in English
Analysis methods are currently being miniaturized in order to save time and money while achieving higher
sensitivities. The ultimate goal is to create a lab-on-a-chip where all analysis steps and instruments can be
automated and integrated into a single chip. In order to perform cellassays and microparticle based
bioassays on chip, methods to manipulate particles and cells in microsystems are desired. This thesis
describes the development of a non-contact method of manipulating cells and particles in lab-on-a-chip
systems based on ultrasonic standing waves. A short review on microfluidics and acoustics is presented,
followed by an overview of other techniques for trapping particles and cells in microsystems. Previous work
done within the field of acoustic trapping in macro- and microsystems is reviewed before the development
and fabrication of the acoustic trapping platform is presented. The trapping platform provides a noncontact
way of immobilizing cells and particles in a continuously flowing microsystem. The possiblity to
use an array of trapping sites and move particles between different trapping sites is demonstrated. A model
bioassays is presented to show the potential of the dynamic arraying concept, where the combination of
microfluidics and an array of non-contact trapping sites is used to create a flexible platform for particlebased
assays. The platform is also shown to be a gentle way of immobilizing live cells as demonstrated by
culturing yeast cells suspended in a standing wave. A viability assay on levitated neural stem cells is also
performed to show handling of a more sensitive cell type. The technique is applied to the field of forensics
in sample preparation for DNA-analysis in rape cases. The acoustic technique is shown to achieve
comparable purities of the separated DNA fraction in a substantially shorter time as compared to the
standard methods used today. The results show that the acoustic trapping platform is a flexible and gentle
cell handling technique and has the potential to become an important tool for cell and particle handling in
microfluidic systems. Finally, an all-glass wet-etched device for acoustic continuous flow separations was
demonstrated. Previously reported devices have been manufactured in silicon and the possibility to use
glass as base material will lower the chip costs, simplifies the fabrication process and decrease the
fabrication time.
sensitivities. The ultimate goal is to create a lab-on-a-chip where all analysis steps and instruments can be
automated and integrated into a single chip. In order to perform cellassays and microparticle based
bioassays on chip, methods to manipulate particles and cells in microsystems are desired. This thesis
describes the development of a non-contact method of manipulating cells and particles in lab-on-a-chip
systems based on ultrasonic standing waves. A short review on microfluidics and acoustics is presented,
followed by an overview of other techniques for trapping particles and cells in microsystems. Previous work
done within the field of acoustic trapping in macro- and microsystems is reviewed before the development
and fabrication of the acoustic trapping platform is presented. The trapping platform provides a noncontact
way of immobilizing cells and particles in a continuously flowing microsystem. The possiblity to
use an array of trapping sites and move particles between different trapping sites is demonstrated. A model
bioassays is presented to show the potential of the dynamic arraying concept, where the combination of
microfluidics and an array of non-contact trapping sites is used to create a flexible platform for particlebased
assays. The platform is also shown to be a gentle way of immobilizing live cells as demonstrated by
culturing yeast cells suspended in a standing wave. A viability assay on levitated neural stem cells is also
performed to show handling of a more sensitive cell type. The technique is applied to the field of forensics
in sample preparation for DNA-analysis in rape cases. The acoustic technique is shown to achieve
comparable purities of the separated DNA fraction in a substantially shorter time as compared to the
standard methods used today. The results show that the acoustic trapping platform is a flexible and gentle
cell handling technique and has the potential to become an important tool for cell and particle handling in
microfluidic systems. Finally, an all-glass wet-etched device for acoustic continuous flow separations was
demonstrated. Previously reported devices have been manufactured in silicon and the possibility to use
glass as base material will lower the chip costs, simplifies the fabrication process and decrease the
fabrication time.
Avdelning/ar
Publiceringsår
2008
Språk
Engelska
Fulltext
Dokumenttyp
Doktorsavhandling
Förlag
Lund University
Ämne
- Medical Engineering
Nyckelord
- acoustic particle manipulation
- standing waves
- trapping
- ultrasound
- cell handling
- particle handling
- Microsystem technology
- lab on a chip
- microfluidics
Status
Published
Handledare
ISBN/ISSN/Övrigt
- ISBN: 978-91-628-7525-1
Försvarsdatum
5 juni 2008
Försvarstid
13:15
Försvarsplats
Room E:C, E-building, Ole Römers väg 3, Lund university, Faculty of Engineeringb
Opponent
- Jürg Dual (Professor)