Nanolithography with molecules using advanced scanning probe microscopy methods

The possibilities of novel catalytic scanning probe lithography (cSPL) on starch using α-amylase was investigated. For this thin homogeneous layers of starch with good coverage were prepared by spin coating a starch solution on a silicon base. Amylase immobilized to an atomic force microscopy (AFM) cantilever tip were prepared and dragged along a spin coated starch surface. This after verifying the enzyme immobilization method using (3-Aminopropyl)triethoxysilane (APTES) on a silicon surface. In addition an unmodified cantilever tip were dipped in amylase solution and were dragged along a starch surface to investigate possibilities of dip-pen nanolithography (DPN). The preliminary experiments with AFM based enzymatic lithography were promising but non-conclusive. There are still many parameters not fully explored such as water availability, activity and reach of the amylase, speed of the enzymatic process and difference in structure between the starch and the shorter saccharides that are left after the hydrolysi

Nanolithography with molecules using advanced scanning probe microscopy methods

The possibilities of novel catalytic scanning probe lithography (cSPL) on starch using α-amylase was investigated. For this thin homogeneous layers of starch with good coverage were prepared by spin coating a starch solution on a silicon base. Amylase immobilized to an atomic force microscopy (AFM) cantilever tip were prepared and dragged along a spin coated starch surface. This after verifying the enzyme immobilization method using (3-Aminopropyl)triethoxysilane (APTES) on a silicon surface. In addition an unmodified cantilever tip were dipped in amylase solution and were dragged along a starch surface to investigate possibilities of dip-pen nanolithography (DPN). The preliminary experiments with AFM based enzymatic lithography were promising but non-conclusive. There are still many parameters not fully explored such as water availability, activity and reach of the amylase, speed of the enzymatic process and difference in structure between the starch and the shorter saccharides that are left after the hydrolysi

Carbon Nanotube Raman Spectra Calculations using Density Functional Theory

Utilizing density functional theory (DFT) the Vienna Ab initio Simulation Package (VASP) was used to calculate the Raman spectra for five single-walled carbon nanotubes (SWCNTs) with chiralities (4,4), (6,6), (8,0), (12,0) and (7,1). The radial breathing mode (RBM), when compared with experimental frequencies, shows good correlation. When compared to RBM:s calculated with tight binding the frequencies calculated with DFT displayed higher accuracy. The precision of G-band frequencies were inconclusive due to lack of experimental data. The frequencies did not agree well with the results from tight-binding theory. The correctness of the Raman activity estimations using results from DFT calculations was found to be questionable. An unknown mode, which was found to be highly Raman active in the calculated spectra of (4,4), (6,6), and possibly (8,0), and (12,0), is also discussed. It was concluded that further calculations on larger tubes, especially armchair tubes are relevant for future studies. Further verification of the determination of Raman activity is also needed.Supervisors: Daniel Hedman, Andreas Larsson and Sven ÖbergF7042T - Project in Engineering Physic

Concurrent Validity of Cervical Movement Tests Using VR Technology—Taking the Lab to the Clinic

Reduced cervical range of motion (ROM) and movement velocity are often seen in people with neck pain. Objective assessment of movement characteristics is important to identify dysfunction, to inform tailored interventions, and for the evaluation of the treatment effect. The purpose of this study was to investigate the concurrent validity of a newly developed VR technology for the assessment of cervical ROM and movement velocity. VR technology was compared against a gold-standard three-dimensional optical motion capture system. Consequently, 20 people, 13 without and 7 with neck pain, participated in this quantitative cross-sectional study. ROM was assessed according to right/left rotation, flexion, extension, right/left lateral flexion, and four diagonal directions. Velocity was assessed according to fast cervical rotation to the right and left. The correlations between VR and the optical system for cervical ROM and velocity were excellent, with intraclass correlation coefficient (ICC) values &gt; 0.95. The mean biases between VR and the optical system were ≤ 2.1° for the ROM variables, &lt;12°/s for maximum velocity, and ≤3.0°/s for mean velocity. In conclusion, VR is a useful assessment device for ROM and velocity measurements with clinically acceptable biases. It is a feasible tool for the objective measurement of cervical kinematics in the clinic.Validerad;2024;Nivå 2;2024-01-01 (hanlid);Full text license: CC BY</p