Strongly nonlinear phononic crystals
The study of the wave propagation characteristics of few grains of sand has led in the past to the discovery of an all new area of strongly nonlinear wave dynamic. Its beauty stems from the combination of its apparent simplicity and the hidden self-organized complexity, leading to a revolutionary type of materials behavior.
We study new 1-, 2- and 3-dimensional strongly nonlinear phononic crystals to contribute to the theoretical and experimental investigation of the basic phenomena guiding the wave propagation in these systems. The physical aspects at the foundation of these metamaterials reside in a completely new type of solitary waves, characterized by a finite length, an extremely fast decomposition of the initial impulse on very short distances and on the fine tunability of the wave properties and band gaps by an applied prestress (i.e. by magnetically induced precompression).
Further investigation of these 3-dimensional strongly nonlinear materials at nano- micro- and millimeter scales will have a broad impact on the whole area of nonlinear wave dynamics creating experimental basis for new theories and models as it was widely demonstrated earlier in simple 1-D cases of “sonic vacuum” (systems with no characteristic acoustic waves speed).
We are interested in exploring various potential applications of the newly designed materials toward the development of tunable acoustic lenses and shock protecting devices. Probable analogies with electrical and optical strongly nonlinear lines can be prompted as a result of this activity.

 

Surface engineering for contact interaction control
To better tune the nonlinear dynamic properties of layered materials, we are interested in engineering the contact interactions between the elements of the system. The CVD growth of various nano-structures, carbon nanotubes, nanowires, etc. is desirable to tube the mechanical response of our metamaterials and to discover new wave phenomena for various applications in light weight heterogeneous structures for protecting layers and energy absorbing devices.

 

 

Biomaterials
The combination of micro-, nano-devices and materials with biomedical problems is now receiving much attention from the scientific community. This synergy can be exploited for answering a variety of different biomedical questions and can be applied to various bioengineering applications (ranging from possible rapid DNA sequencing methods to the understanding of the localized effects of drugs acting on the cell membranes and optimized cell growth and their enhanced bioactivity). The study of cell mechanics, the ionic transport through nanoscale pores, the nanotube-enhanced cell proliferation and the possible integration with microfluidic devices are all good examples. In addition, the study of the flow of biologic fluids through narrow pores and channels will allow interesting experiments with direct practical applications for molecules and cell detection, filtering, counting, sorting and medical diagnostics.

 

Advanced and in-situ characterization of nano- and biological materials
Advanced characterization techniques play a vital role on materials science. They represent the key factor for research advancements in all areas related to nano- and bio-materials.
Conventional, well known TEM, AFM and FIB microscopy techniques, combined with in-situ testing (stress-strain, temperature, optical and electrical behavior) and tomography are part of our lab’s efforts to characterize new materials and their mechanical behavior.

One other project now being developed is aimed at investigating the origin of life: can SEM and TEM help finding a signature of the oldest form of life? A structural study of the carbon forms found in the oldest sedimentary rocks on earth may help finding an answer to this question.