Sascha Hilgenfeldt

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Sound driven gas bubbles in water can emit light pulses. This phenomenon is called sonoluminescence ͑SL͒. Two different phases of single bubble SL have been proposed: diffusively stable and diffusively unstable SL. We present phase diagrams in the gas concentration versus forcing pressure state space and also in the ambient radius versus gas concentration(More)
The ability of collapsing (cavitating) bubbles to focus and concentrate energy, forces and stresses is at the root of phenomena such as cavitation damage, sonochemistry or sonoluminescence. In a biomedical context, ultrasound-driven microbubbles have been used to enhance contrast in ultrasonic images. The observation of bubble-enhanced(More)
We describe the development and application of an imaging protocol, which evolves a scanning probe's atomic structure in parallel with automated optimization of the scan parameters. Our protocol coerces the system into a state that produces a specific atomic resolution image type without human involvement. Abstract We use numerical simulations to(More)
While solid mechanics has long dealt with traditional "hard" solids such as metals or amorphous materials, recent research in a variety of disciplines focuses on the understanding of Soft Matter-which turns out to be a harder problem in many respects. Soft matter is at the center of research in foams, suspensions, emulsions, slurries, and other composite(More)
Tiny collapsing bubbles can focus acoustic energy into bursts of visible light. Careful measurements of the emitted light reveal extraordinary conditions at the centre of the implosion of a single bubble, but not so extraordinary as to support fantastical claims. S onoluminescence is the astounding phenomenon that converts sound energy into visible light.(More)
Cells in the Drosophila retina have well-defined morphologies that are attained during tissue morphogenesis. We present a computer simulation of the epithelial tissue in which the global interfacial energy between cells is minimized. Experimental data for both normal cells and mutant cells either lacking or misexpressing the adhesion protein N-cadherin can(More)
The regular hexagonal array morphology of facets (ommatidia) in the Drosophila compound eye is accomplished by regulation of cell differentiation and planar cell polarity during development. Mutations in certain genes disrupt regulation, causing a breakdown of this perfect symmetry, so that the ommatidial pattern shows onset of disorder in the form of(More)
—Confocal microscopy has been experimentally proven for decades to provide high-quality images for biological research. Its unique property of blocking out-of-focus light enables 3D rendering from planar stacks and visualization of internal features. However, visualizing 3D data on a flat display is not intuitive, and would lead to occasional distortion. In(More)