Completed projects

Several goals were pursued in the devel­op­ment of this work, includ­ing the devel­op­ment of a novel in vivo method to measure the ciliary muscle of a human subject non-invasively during accom­mo­da­tion, the charac­ter­i­za­tion of the recorded muscle signals based on the accom­moda­tive abili­ties of the subject, and the devel­op­ment of a device that would utilize the recorded muscle signals to mimic the appro­pri­ate level of accom­mo­da­tion for the user, actuated through the use of a variable refrac­tive lens.

The risk to develop posttrau­matic stress disor­der (PTSD) depends on the number of traumatic events experi­enced and individ­ual risk factors, e.g. genetic predis­po­si­tions. However, to identify causal genetic variants of this polygenic disease, trauma exposure needs to be adequately assessed.

Fossil resources are increas­ingly depleted. They have to be replaced as quickly as possi­ble by renew­able raw materi­als, so that a slow transi­tion to a new and modern produc­tion of „platform chemi­cals“ can take place.

The market’s demand for carbon fiber/epoxy compos­ite has dramat­i­cally increased due to its signif­i­cant appli­ca­tions and advan­tages in indus­try. Typical loading on the struc­tures that are made up by this mater­ial often involves tensile and lateral bending of the compos­ite laminates.

The exact position of atoms in the crystal struc­ture of lanthanum mangan­ites and cobal­tates (both anorganic ionic compounds) signif­i­cantly affects their magnetic proper­ties. The crystal struc­ture of these materi­als can be altered by pressure, substi­tu­tion of elements, or crystal­lite size: Since nanopar­ti­cles have a large surface-to-volume ratio, their surface has a dominant effect on the crystal struc­ture, leading to changes compared to bulk materials.

Metama­te­ri­als are ratio­nally designed struc­tures exhibit­ing effec­tive macro­scopic mater­ial proper­ties that go beyond those of ordinary materi­als. For instance, by intro­duc­ing so-called topolog­i­cally protected resonances it is possi­ble to locally enhance mechan­i­cal vibra­tions and make them robust against pertur­ba­tions. In this project, chiral metama­te­ri­als with topolog­i­cally protected resonances are designed and fabri­cated to realize a resonant mechan­i­cal laser-beam scanner (see Figure). Such laser-beam scanners are crucial for various appli­ca­tions such as LIDAR, confo­cal microscopy, projec­tor displays, and mater­ial processing.

A rich variety of phenom­ena in solid state systems such as quantum magnet­ism or high temper­a­ture super­con­duc­tiv­ity still pose open questions on parts of their micro­scopic expla­na­tion. Due to the complex­ity of these systems, the under­ly­ing quantum many-body dynam­ics is often not acces­si­ble to compu­ta­tional simulation.

Increased anthro­pogenic activ­i­ties and climate change are causing a global shift in patterns of water fluxes. Semi-arid river basins are charac­ter­ized by more water stresses, extreme and sporadic climatic events, and have been projected to worsen in many regions under the influ­ence of climate change.

Galac­tic archae­ol­ogy uses stars as fossils to study the evolu­tion­ary history of galax­ies like our own Milky Way. Cosmo­log­i­cal simula­tions suggest that larger galax­ies were partially formed by accret­ing smaller dwarf galax­ies. Such merger events should leave observ­able signa­tures in the form of star streams, but empir­i­cal constraints on the times, numbers, and impor­tance of such mergers are still missing.

In modern condensed matter physics topol­ogy plays a funda­men­tal role in the classi­fi­ca­tion of phases of matter. A promi­nent example is the quantum Hall effect discov­ered in two-dimen­sional electron gases under extreme condi­tions. Quantum Hall insula­tors are isolat­ing in the bulk, but exhibit conduct­ing edge states, which results in a quantised Hall conductance.

Cichlid fish are well-known for their beauti­ful colors and multi­tude of body shapes. They are found in the East African Rift lakes where they have formed so-called adaptive radia­tions, in which hundreds of new species origi­nated extremely quickly – sometimes within less than 100,000 years.

Preva­lence of myopia (short­sight­ed­ness) increases consid­er­ably in indus­tri­al­ized countries. The mecha­nisms behind this devel­op­ment need to be fully under­stood in order to arrive at preven­tion. The aim of Sandra Wagner’s research was to allow a better under­stand­ing of accom­mo­da­tion, address unanswered question regard­ing myopia onset and support the devel­op­ment of new devices.