- Mechanical properties of silica aerogels
Silica aerogels are nanostructured, highly porous solids, which have, compared to other soft materials, special mechanical properties, such as extremely low densities. In this project, the mechanical properties of silica aerogels have been studied with molecular dynamics simulations. The silica aerogel model was created by direct expansion of beta-cristobalite, along with a series of thermal treatments. The mechanical properties of the silica-aerogel-molecular-dynamics-model in uniaxial tension and compression were studied. Moreover, cyclic loading simulations, under compression, were carried out on the silica models of the different densities. Under larger strains, nearly no recovery of the collapsed structural network was observed. The response is characterised by inelastic phenomena like residual deformation, hysteresis, and Mullins effect.
- Inertial sensor based motion analysis
In this project a system is developed that is able to determine kinematic and kinetic motion patterns based on inertial sensors and intelligent algorithms. Most motion analysis systems available on the market are limited to laboratory conditions. Low-cost, highly flexible inertial measurement units combined with smartphones offer the opportunity to determine motion patterns during daily life. In the future, motion pathologies shall be detected online and feedback given to the user. Thereby, we receive a valuable tool to support the self-reliance of the aging society, to evaluate post-operation changes or to support people in learning gait strategies, e.g. to avoid further damage of the knee joint.
- Vertebral motion measurement of lumbar spine in 6 degree of freedom spine testing rig at body temperature for testing of dynamic spine instrumentations
In this study, the influence of spine instrumentations on the range of motion of functional spinal units is tested on lumbar spines. To this end, a 6 degree of freedom spine testing rig with a bioreactor of a former study has been developed to test under physiological conditions. The use of a bioreactor impedes mechanical and optical measurement approaches, which is accomplished by use of a special magnetic tracking system with implantable micro receivers. Further the effects of instrumentations on the spinal kinematics are assessed via FE simulations.
- Department of Orthopedic Trauma and Reconstructive Surgery (UCH RWTH)
- RWTH Start Nachwuchsförderprogramm
- Department of Orthopedic Trauma and Reconstructive Surgery University Hospital Cologne
- Department of Orthopedic Trauma and Trauma Surgery Medical Centre CR Aachen GmbH
- Mechanical properties of nacre and its constituentsCopyright: © IAM
Nacre, also known as the Mother of Pearl is an organic-inorganic composite material produced by some molluscs as an inner shell layer. In the last three decades, the structure and the toughening mechanism of nacre have been the subject of intensive research. This interest originates from nacre's excellent combination of strength, stiffness and toughness. It is composed of hexagonal platelets of aragonite arranged in a continuous parallel lamina. The layers are separated by sheets of organic matrix composed of elastic biopolymers. This mixture of brittle platelets and the thin layers of elastic biopolymers make the material strong and resilient.