Advances in Soft Matter Nanofabrication

The focus of this thesis is placed on the fabrication of engineered nanodevices for the manipulation of soft matter thin films. By combining top-down micro- and nanofabrication approaches with bottom-up self-assembly strategies, new research platforms were developed, tested and characterized. A large part of the studies described herein were performed on electron beam-sculpted Teflon AF surfaces, which served as substrate for molecular lipid films and biological cells. The effects of e-beam exposure of Teflon AF deposits, including changes in hydrophobicity, topography, surface potential and roughness, have been investigated in detail. Lipophilic nanolanes of 50 nm width were created in this manner. The studies show, for example, how spreading of a phospholipid monolayer film originating from a single giant multilamellar vesicle source can be confined and guided by e-beam-exposed frames on the polymer surface. The studies also reveal the preferential adhesion of biological cells on these e-beam-treated Teflon AF surfaces, where the shape of the patterned areas strongly affects cell adhesion. By applying perfluorinated solvent as developer to complete the ebeam-lithography procedure, Teflon AF was introduced as non-amplified negative e-beam resist. Nanostructures with feature sizes as small as 30 nm in width and 40 nm in pitch were fabricated. This new resist was characterized by determining its contrast, sensitivity, and film thickness. The accommodation of single DNA origami scaffolds on developed Teflon AF nanopillars has been investigated as an exemplary application, and about 80% coverage of the available pillar surface was achieved. Moreover, a novel, contact-free technology was developed to generate surface-supported networks of lipid nanotubes and flat giant unilamellar vesicles on a micro-patterned SU-8 substrate. The nanotubes were formed by thermomigration of a phospholipid double bilayer, where the migration of lipid material on the patterned surface was initiated and controlled by a temperature gradient created with an IR laser. In the work presented here, a number of specific problems have been tackled in an interdisciplinary approach, making use of micro- and nanotechnologies, new materials and biomimetic principles that can open up new experimental opportunities to address further fundamental research questions

Advances in Soft Matter Nanofabrication

The focus of this thesis is placed on the fabrication of engineered nanodevices for the manipulation of soft matter thin films. By combining top-down micro- and nanofabrication approaches with bottom-up self-assembly strategies, new research platforms were developed, tested and characterized.A large part of the studies described herein were performed on electron beam-sculpted Teflon AF surfaces, which served as substrate for molecular lipid films and biological cells. The effects of e-beam exposure of Teflon AF deposits, including changes in hydrophobicity, topography, surface potential and roughness, have been investigated in detail. Lipophilic nanolanes of 50 nm width were created in this manner. The studies show, for example, how spreading of a phospholipid monolayer film originating from a single giant multilamellar vesicle source can be confined and guided by e-beam-exposed frames on the polymer surface. The studies also reveal the preferential adhesion of biological cells on these e-beam-treated Teflon AF surfaces, where the shape of the patterned areas strongly affects cell adhesion.By applying perfluorinated solvent as developer to complete the ebeam-lithography procedure, Teflon AF was introduced as non-amplified negative e-beam resist. Nanostructures with feature sizes as small as 30 nm in width and 40 nm in pitch were fabricated. This new resist was characterized by determining its contrast, sensitivity, and film thickness. The accommodation of single DNA origami scaffolds on developed Teflon AF nanopillars has been investigated as an exemplary application, and about 80% coverage of the available pillar surface was achieved.Moreover, a novel, contact-free technology was developed to generate surface-supported networks of lipid nanotubes and flat giant unilamellar vesicles on a micro-patterned SU-8 substrate. The nanotubes were formed by thermomigration of a phospholipid double bilayer, where the migration of lipid material on the patterned surface was initiated and controlled by a temperature gradient created with an IR laser. In the work presented here, a number of specific problems have been tackled in an interdisciplinary approach, making use of micro- and nanotechnologies, new materials and biomimetic principles that can open up new experimental opportunities to address further fundamental research questions

Ersättning av metylenklorid vid asfaltsextraktioner : Förstudie

I flera provningsmetoder av asfaltmaterial, behöver man lösa upp bindemedlet i asfalten, bituminet, med hjälp av ett lösningsmedel. Det lösningsmedel som de flesta asfaltslaboratorier använder i Sverige, är metylenklorid. Metylenklorid eller diklormetan, som är ett annat namn för samma lösningsmedel, är ett halogenerat lösningsmedel, som effektivt löser fett, vax och harts. Å andra sidan kan exponering av metylenklorid leda till hälsorisker som yrsel, trötthet, illamående, huvudvärk och domningar, blodstörningar och det finns även misstankar om cancer, mutation och fosterskador. Dessutom har metylenklorid skadliga långtidseffekter för vattenlevande organismer och bör därför inte släppas ut i miljön och vatten. Denna förstudie syftar till att undersöka möjligheten att ersätta metylenklorid med ett eller flera, ur miljö- och arbetsmiljöperspektiv bättre lösningsmedel, som kan användas till extraktion och återvinning av bindemedel från asfalt. Skulle det gå att ersätta metylenklorid med ett bättre lösningsmedel, kan samtliga laboratorier i branschen börja driva sina verksamheter på ett mer miljövänligt sätt och samtidigt få en säkrare arbetsmiljö

Contactless Stimulation and Control of Biomimetic Nanotubes by Calcium Ion Gradients

Membrane tubular structures are important communication pathways between cells and cellular compartments. Studying these structures in their native environment is challenging, due to the complexity of membranes and varying chemical conditions within and outside of the cells. This work demonstrates that a calcium ion gradient, applied to a synthetic lipid nanotube, triggers lipid flow directed toward the application site, resulting in the formation of a bulge aggregate. This bulge can be translated in a contactless manner by moving a calcium ion source along the lipid nanotube. Furthermore, entrapment of polystyrene nanobeads within the bulge does not tamper the bulge movement and allows transporting of the nanoparticle cargo along the lipid nanotube. In addition to the synthetic lipid nanotubes, the response of cell plasma membrane tethers to local calcium ion stimulation is investigated. The directed membrane transport in these tethers is observed, but with slower kinetics in comparison to the synthetic lipid nanotubes. The findings of this work demonstrate a novel and contactless mode of transport in lipid nanotubes, guided by local exposure to calcium ions. The observed lipid nanotube behavior can advance the current understanding of the cell membrane tubular structures, which are constantly reshaped during dynamic cellular processes

Nanopatterning of Mobile Lipid Mono layers on Electron-Beam-Sculpted Teflon AF Surfaces

Direct electron-beam lithography is used to fabricate nanostructured Teflon AF surfaces, which are utilized to pattern,surface-supported monolayer phospholipid films with 50 nm lateral feature size. In comparison with unexposed Teflon AF coatings, e-beam-irradiated areas show reduced surface tension and surface potential. For phospholipid monolayer spreading experiments, these areas can be designed to function as barriers that enclose unexposed areas of nanometer dimensions and confine the lipid film within. We show that the effectiveness of the barrier is defined by pattern geometry and radiation dose. This surface preparation technique represents an efficient, yet simple, nanopatterning strategy supporting studies of lipid monolayer behavior in ultraconfined spaces. The generated structures are useful for imaging studies of biomimetic membranes and other specialized surface applications requiring spatially controlled formation of self-assembled, molecularly thin films on optically transparent patterned polymer surfaces with very low autofluorescence

Nanopatterning of Mobile Lipid Monolayers on Electron-Beam-Sculpted Teflon AF Surfaces

Direct electron-beam lithography is used to fabricate nanostructured Teflon AF surfaces, which are utilized to pattern surface-supported monolayer phospholipid films with 50 nm lateral feature size. In comparison with unexposed Teflon AF coatings, e-beam-irradiated areas show reduced surface tension and surface potential. For phospholipid monolayer spreading experiments, these areas can be designed to function as barriers that enclose unexposed areas of nanometer dimensions and confine the lipid film within. We show that the effectiveness of the barrier is defined by pattern geometry and radiation dose. This surface preparation technique represents an efficient, yet simple, nanopatterning strategy supporting studies of lipid monolayer behavior in ultraconfined spaces. The generated structures are useful for imaging studies of biomimetic membranes and other specialized surface applications requiring spatially controlled formation of self-assembled, molecularly thin films on optically transparent patterned polymer surfaces with very low autofluorescence

Thermal migration of molecular lipid films as a contactless fabrication strategy for lipid nanotube networks

We demonstrate the contactless generation of lipid nanotube networks by means of thermally induced migration of flat giant unilamellar vesicles (FGUVs), covering micro-scale areas on oxidized aluminum surfaces. A temperature gradient with a reach of 20 mm was generated using a focused IR laser, leading to a surface adhesion gradient, along which FGUVs could be relocated. We report on suitable lipid-substrate combinations, highlighting the critical importance of the electrostatic interactions between the engineered substrate and the membrane for reversible migration of intact vesicles