Recent News

Publication on the effect of geometry on the DNA waves.

[13 FEB 2024]

Recently our paper on the effect of geometry on the #DNAwaves came out in Micromachines. We explore the effect of the array geometry for three distinct geometries: square array, hexagonal array and random array. The resulting waves are dramatically different for the three cases. While the waves are highly regular and distinct for the square array, they are more turbulent like in the hexagonal array and essentialy absent in the random array.

Paper on effect of geometry on the DNA waves

Publication on the effect of symmetry on the DNA waves.

[27 OCT 2023]

Recently our paper on the effect of symmetry on the #DNAwaves came out in RSC Advances. The basic idea is that while the #DNAwaves occur in two types (LEFT and RIGHT) for arrays with round pillars, breaking the lateral symmetry in the shape of the pillars, we only see one of the types (LEFT or RIGHT). We can thus control the behavior of the DNAwaves on the millimeter scale by changing details on the 10um scale in the array.

Paper on effect of symmetry on the DNA waves

Oskar Ström successfully defended his thesis on DNA purification and non-Newtonian wave phenomena in microfluidic channels.

[10 FEB 2023]

One main motivation for the project was to sort DNA with the intent to have highly purified ultralong DNA in large quantities. During the investigations, concentration waves were observed in the flow of highly concentrated DNA at hiogh flow rates in microfluidic pillar arrays. The thesis covers the initial work on puriffying DNA using DLD followed by a few manuscripts on the characterization of the resulting wave patterns in different types of pillar arrays.

Paper on ultra-high-throughput DNA sorting and purification

First paper describing the waves

Manuscript on the effect of symmetry on the waves

Oskar's PhD thesis

Bao Dang Ho recently published two papers in Micromachines on electrokinetic sorting of micro and nanoscale particles.

[JAN 2021]

Electrokinetic effects are combined with deterministic lateral displacement to sort particles ranging from lipid vesicles to bacteria and yeast based on primarily on zeta potential.

Abstract for Bao's first paper

Abstract for Bao's second paper

Cover story for Bao's second paper

Cover image for Bao's second paper

We have received funding from the Swedish-Norwegian Foundation for Equine Research for our project "Diagnosis of parasitic diseases in horses using microfluidics and cell-phone based microscopy".

[16 Dec 2019]

Together with Dr Eva Tydén at the Swedish Agricultural University in Uppsala we will develop a diagnostic system based on microfluidic separation of fecal samples. The samples are treated in different steps so that the eggs of interest can be sorted and then analyzed using primarily cellular phone-based microscopy but also on-chip DNA analysis. We expect our microfluidic system for the diagnosis of fecal samples is faster, easier to use, more sensitive, more accurate and less expensive than today's systems.

We have received funding from the Swedish Research Council for the research environment "Multiscale biomechanics from molecules to cells in cancer".

[10 Dec 2019]

Together with Ass Prof Vinay Swaminathan, Ass Prof Pontus Nordenfelt and Assoc Prof Chris Madsen, we will test the relationship between the bio-mechanical phenotypes of cancer cell populations, cell lines as well as metastasized circulating tumor cells (CTCs) the fundamental cellular property of directed cell migration and investigate the molecular mechanisms that govern these properties. We will combine unique technological advances from microfluidics and advanced optical microscopy, including super resolution microscopy to shed new light on a central disease mechanism, and in the end open up for novel diagnostics and more precise treatments of cancer.

We have received funding from the Swedish Research Council for our project "Morphology and virulence among bacteria".

[31 Oct 2019]

Bacterial morphology has been used for long time to classify bacterial species and strains. However, it has not been investigated to any great extent what benefits different morphologies confer to the bacteria or what challenges they may face for certain morphologies.
In a collaboration between Physics and Medicine (Ass Prof Pontus Nordenfelt) we will study the effect of morphology of bacteria and bacterial clusters by advanced microfluidics for sorting of the bacteria as a function of their physical properties, followed by detailed investigations of their interaction with the human cell lines as a function of their properties. The aim is to gain knowledge how the physical properties of the bacteria affect their interaction with the host.

Together with recent PhD Feifei Peng from Physical Chemistry we published a study in the Journal of Physicsal Chemistry B on tunable colloidal molecules prepared using droplet fluidics.

[4 Oct 2019]

Small clusters of spherical colloids that mimic real molecules, so-called colloidal molecules, hold great promise as building blocks in bottom-up routes to new materials. However, their typical hard sphere nature has hampered their assembly into ordered structures, largely due to a lack of control in the interparticle interactions. To provide easy external control of the interactions, we have used droplet fluidics to prepare colloidal molecules from temperature-responsive microgel particles that undergo a transition from a soft repulsive to a short-range attractive state as their characteristic volume phase transition temperature (VPTT) is crossed.The work was done in collaboration with the Schurtenberger group at Physical Chemistry at Lund University.

Abstract of Feifei Peng's first paper

Abstract of another pap[er by Feifei Peng where we had a minor role

Stefan Holm published a study in Physical Review Applied on the effect of hematocrit on the sorting capabilities of DLD.

[26 July 2019]

Particle-particle interactions influence the sorting capability of DLD. Here we have studied the effect of increasing hematocrit on the sorting of microspheres. It was found that microspheres of size much larger and much smaller than the critical size are not affected by the hematocrit while particles close to the critical size exit teh array at an intermediate position. The work was done within the EU project LAPASO in collaboration with the Gompper group at Forschungszentrum Jülich.

Abstract of Stefan Holm's paper on the effect of hematiocrit on sorting

Jason Beech demonstrated a novel type of DLD array in Advanced materials Technologies.

[11 July 2019]

Active posts in DLD - by making the posts in the DLD array active electrodes we achieve high fields even with minute applied voltages. We demonstrate deflection of nanosclae particles opening up for nanoscale particle separation in devices designed with micrometer featres. The work was done in collaboration with the Guiducci group at EPFL.

Abstract of Jason Beech's paper on DLD with active posts

Cover for Jason Beech's paper on DLD with active posts

Trung Si Hoai Tran successfully defended his thesis entitled Deterministic Lateral Displacement for Cell Separation, 14 June 2019 at 9:15, at the department of Physics (Rydbergsalen). Professor Nikolaj Gadegaard was the opponent.

[14 June, 2019]

Trung Tran's PhD thesis (pdf, new tab)

The two main contributions discussed in the thesis comprise deformablity based sorting of cancer cells, and deterministic lateral displacement on a surface.

Bao Dang Ho successfully defended his thesis entitled Cell Sorting in Pillar Arrays based on Electrokinetics and Morphology, 23 November 2018 at 9:15, at the department of Physics (Rydbergsalen). Professor Michael Hughes was the opponent.

[November, 2018]

Bao Ho's PhD thesis (optimized pdf, new tab)

The main contribution discussed in the thesis comprises a combination of electrokinetics and deterministic lateral displacement. Fundamental issues are discussed and proof of principle is demonstrated of sorting of bacteria and yeast based on their viability. Both translational and rotation effects are demonstrated. Furthermore, morphological sorting of bacteria is demonstrated.

Tegenfeldt is chair of the Workshop on Labelling and Imaging Techniques in Super-Resolution Microscopy organized in Lund May 28-29 2018

[May, 2018]

Labelling is considered a major factor influencing the quality and the information obtainable in super-resolution microscopy. The workshop will cover different labelling strategies and imaging modalities along with applications in STED, STORM, FPALM and other types of super resolution microscopy techniques.

SupTech website

Detailed program for the SupTech workshop

Stefan Holm successfully defended his PhD thesis entitled Microfluidic Cell and Particle Sorting using Deterministic Lateral Displacement, 16 March 2018 at 14:15, at the department of Physics (Rydbergsalen). Prof Brian Kirby was the opponent.

[March, 2018]

Stefan Hiolm's PhD thesis (optimized pdf, new tab)

The main contributions discussed in the thesis comprise morphological sorting, specifically with applications in parasite enrichment, density based sorting, fundamental study of the effect of hematocrit in DLD devices, and fabrication of colloidal molecules using droplet fluidics.

Kushagr Punyani successfully defended his Licentiate thesis entitled Label-free particle sorting: technology and biological applications, 14 March 2018 at 10:15, at the department of Physics (H221). Dr Håkan Jönsson was the opponent.

[March, 2018]

Kushagr Punyani 's Licentiate thesis

Review paper on microfluidic isolation of parasites in Pathogens

[October, 2017]

We published a review paper covering techniques to isolate African trypanosomes in the journal Pathogens together with a consortium financed through the project LAPASO.

Abstract of review paper on microfluidic isolation of parasites

Trung Tran's paper on open DLD is accepted for publication in Lab on a Chip

[September, 2017]

A DLD device without cover is demonstrated for sorting of polymer microspheres and different types of cells. The benefit of the open architecture is that the device is easy to clean and less prone to clogging compared to conventional closed microfluidics. The device is driven by a paper capillary pump opening up for applications based on paper fluidics.

Abstract of Trung Tran's paper on open DLD

Tegenfeldt is chair of the European Workshop on Label Free Particle Sorting organized in Lund September 5-6 2017

[September, 2017]

The Initial Training Network (EU/FP7) "Label Free Particle Sorting", LAPASO, has brought together 15 partners from academia, industry, government and other actors to develop technologies based on microfluidic label free sorting for application in bacteriology, parasitology and rare cells. The project is rounded off by a workshop organized in Lund September 5-6 2017.

Review paper on optical DNA mapping published in BioTechniques

[June, 2017]

We published a review paper covering optical DNA mapping techniques in BioTechniques together with a consortium financed through the project NanoDiaBac.

Abstract of review paper on optical DNA mapping

Patent granted on DNA labeling scheme based on localized melting

[21 March, 2017]

The US Patent Office has granted a patent (US 9,597,687) for a method to label DNA that was developed in our lab in a collaboration with DTU and Risø National Laboratory in Denmark. The technique gives a barcode pattern along the DNA that can be used to identify fragments of DNA for applications in for example microorganism identification, genome assembly and characterization of structural variations. The technique is described in:

Our paper on localized melting from 2010 in PNAS.

Project on a DNA barcode reader based on a cell phone for diagnostics

[19 January, 2017]

We have been granted funding from the Swedish Research Council to develop and validate a system to identify pathogens and antibiotic resistance relevant for the developing world. The technology is based on reading out barcode patterns along the DNA using e.g. our melting mapping approach combined with cell-phone based microscopy as developed by Aydogan Ozcan at UCLA. The project will take place in a highly international collaboration among researchers from Europe, USA and Africa.

Bao H Dang earned his Licentiate degree after a successful defense

[June, 2017]

Bao Dang Ho defended hos Licentiate Thesis June 16 2017, entiteled "Deterministic Sorting
by Electrical Properties and Morphology". Opponent was Dr Andreas Dahlin from Chalmers Technical University, Gothenburg, Sweden.

Bao Ho's Lic thesis

Stefan Holm's paper on blood parasites made it to the cover of Analytical Methods

[April, 2016]

Shape based sorting is used to sort out WBC, RBC and parasites from blood using several DLD devices with different array parameters connected in series.

Abstract of Stefan Holm's paper on blood parasites

Cover of Stefan Holm's paper on blood parasites

Tegenfeldt is chair of the Micro Nano System Workshop organized in Lund May 17-18 2016

[January, 2016]

The Micro Nano System Workshop (MSW2016) has been organized every second year for the past 20 years on the theme of micro- and nano-engineering. It covers topics ranging from fundamentals to applications including applications in biology and medicine. New for this year is the opportunity to present live demonstrations. For further details about the meeting, how to submit abstracts and how to plan the demos, please refer to the workshop website.

Workshop website for MSW2016.