Mechanical resonators at micro and nanoscales
B. Erdem Alaca
Department of Mechanical Engineering, Koç University,
Rumelifeneri Yolu, Sarıyer 34450 Istanbul
Mechanical resonators form an important subclass of MEMS/NEMS components. Enabled by batch processing, this new generation of mechanical resonators enjoys significant miniaturization and integration with electronics and other micro/nano systems. This lead to a Moore-type evolution bringing about competitiveness with established technologies and hence raising the prospect for commercialization in many fields. First of all and perhaps in parallel with their historical mission as the timekeeper, they evolved into sophisticated frequency references and filter elements operating over a frequency range from VHF band to microwaves. Miniaturization is as well a determining factor for applications such as mass sensing, where mechanical resonators with ultrahigh sensitivities are achieved. Combined with an appropriate packaging approach, this aspect is as well utilized in physical and more significantly in chemical and biological sensing. In similar terms, immersion of resonators into a fluid enables the measurement of rheological properties thereof.
Our work focuses on micron-sized, metallic cantilevers and silicon nanowires. Targeted areas of application include tunable nanowire filters, biological sensors, and density/viscosity measurements. In MEMS research, demonstrations include human kappa opioid receptors, hepatitis virus markers in liquid samples and phase transformations in carbon dioxide. In nanowire research, emphasis is placed on fabrication aspects, especially batch-compatible integration with actuation and readout components. Along with an overview of the subject the talk will provide details of the aforementioned research topics.
B. Erdem Alaca graduated from Mechanical Engineering Department at Boğaziçi University in 1997. He received his M.S. degree in 1999 and Ph.D. degree in 2003 from the University of Illinois at Urbana-Champaign. After joining Koç University in 2004, he established a cleanroom that now provides university-wide services. He is currently an associate professor in Mechanical Engineering and his research efforts are geared towards mechanical property measurements at micro and nanoscales including the development of accompanying testing devices with specific actuation and readout components. Current focus is placed on batch-compatible fabrication of Si nanowires and development of integration philosophies of these nanowires with micro electromechanical systems, multilayer fracture, development and fabrication of resonant microcantilever-based sensors, characterization of the scale-dependence of thin film mechanical properties.