Events

For more information, please see www.physics.oregonstate.edu/TeachSeminar

My research is focused on applying photodynamic therapy (PDT) towards bone cancers. In PDT, inert photosensitizers (PS) are administered to targeted areas for treatment. Once illuminated by wavelengths specific to the absorption properties of each PS, the PS reaches an excited state and interacts with nearby oxygen, forming reactive species and free radicals. The reactive oxygen and free radicals then damage nearby cells. The goal of PDT is to create sufficient free radicals and reactive oxygen to destroy targeted sites.

Semiconducting carbon nanotubes are extremely sensitive to their electrostatic environment. We use this property to build single-nanotube sensors in liquid environments that detect bio-molecule adsorption in real time via changes in device conductivity. The mechanisms for conductance modulation upon adsorption have been controversial. I will present scanned probe measurements and liquid gating measurements that resolve much of this controversy. We show how modulation of Schottky barrier contacts, together with bulk doping of the nanotubes, lead to gate-dependant changes in conductivity.

For more information, please see www.physics.oregonstate.edu/TeachSeminar

There has been considerable interest in the potential application of terahertz (THz) time domain spectroscopy (TDS) for a variety of problems, including the detection of explosive devices and imaging for biomedical applications. The THz regime has many advantages, including the possibility of a safe (non-ionizing) screening modality and the potential for high-resolution 3D imaging. It also has the advantage of exhibiting spectral peaks that can be used, for example, to classify explosives or detect the presence of cancerous cells.

In this talk, I will present research efforts recently initiated in my laboratory to develop novel magnetic devices. These include biosensors and solid state memory using magnetostrictive thin films. The sensors are based on magnetic bead labeling of target biological and chemical agents, and are envisioned for application in counterterrorism monitoring and bio-medical diagnostics. We are also working on a novel solid state magnetic memory in which the storage and retrieval of data is accomplished by surface acoustic waves (SAWs).

For more information, please see www.physics.oregonstate.edu/TeachSeminar

A quantum system, whose dynamics can be manipulated and controlled at the level of a single photon, is of both fundamental and practical importance. In this talk, I will discuss two promising systems that are based on the use of silica optical resonators. The first system consists of artificial atoms, such as nanocrystals or defect centers, coupling to a resonator mode via a dipole optical transition. The second system exploits the interaction between a mechanical excitation and a resonator mode via radiation pressure.

Knowledge of atomic structural arrangements and composition at surfaces and buried interfaces is fundamental to our understanding of the function and properties of fabricated thin-film structures. Because of favorable cross sections, x-rays offer a unique opportunity to penetrate through gas, liquid, or solid thin-film overlayers to probe the structure and chemistry of surfaces and internal boundaries on the atomic length scale.

For more information, please see www.physics.oregonstate.edu/TeachSeminar

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For more information, please see www.physics.oregonstate.edu/TeachSeminar

Andy Platt: Organic semiconductor materials have attracted significant attention in recent years as they offer significant advantages over traditional silicon technology including their low cost fabrication and tunability through functionalization of the molecules. Projected uses include polymer lasers, flexible displays, and printable photovoltaic cells.