Ongoing Research

Graphene

The photo-thermal therapy using nano-materials has attracted great attention as an efficient strategy for the next generation of cancer treatments. Recently, photo-thermal therapy based on nano-materials that can be activated by a skin-penetrating NIR (Near Infra Red) irradiation has been suggested as a noninvasive, harmless, and highly efficient therapeutic technique. Graphene nano-layers synthesized by a bio-compatible method, with reduced toxicity, will be a suitable candidate for the photo-thermal therapeutic agent. A significant amount of heat is generated upon excitation with near-infrared light (NIR, 700-1100nm) which is transparent to biological species including skins. In this paper, we demonstrate destruction of solid malignant cells (colon cancer cells) by the combined treatments of bio-compatible graphene nano-layers and NIR irradiation. MTT methods show that more than 85% of the cells which held with autoclaved graphene solution remained alive after 24hr. In addition, NIR laser exposure with a 250 mw diode laser (780 nm) to colon cancer cells (without graphene inclusion) for 15 min kills less than 9% of colon cancer cells but  exposing the NIR beam to the graphene-added cells for 25 min kills more than 66% of the cells.

 

Nanorods

A low density plasma reactive ion etching is reported to realize high aspect ratio silicon nanorods on silicon substrates. Aspect ratios with values more than 100 are obtained for features below 200 nm. The process uses a mixture of three gases of hexa-flouro-sulfide, hydrogen and oxygen in a reactive ion etching system with a programmed passivation and etching sub-cycles. Using these three gases in both etching and passivation sub-cycles allows deep silicon etching with high rates, with no need to an ICP source and special cooling system. The mask undercut can be around 30 nm, despite a high etch rate of 0.8-1.1 µm/min. X-ray photo-electron spectroscopy and scanning electron microscopy has been used to investigate the prepared samples. Also Knudsen transport model has been applied on the etching process which results in a value of 0.23 for the “S” value, as the probability for the reaction at the bottom of the craters.

 

Nanowire

A nanowire is a nanostructure, with the diameter of the order of a nanometer (10−9 meters). Alternatively, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. At these scales, quantum mechanical effects are important — which coined the term "quantum wires". Many different types of nanowires exist, including metallic (e.g., Ni, Pt, Au), semiconducting (e.g., Si, InP, GaN, etc.), and insulating (e.g., SiO2, TiO2). Molecular nanowires are composed of repeating molecular units either organic (e.g. DNA) or inorganic (e.g. Mo6S9-xIx). The nanowires could be used, in the near future, to link tiny components into extremely small circuits. Using nanotechnology, such components could be created out of chemical compounds.

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Thin Film Laboratories,

Electric & Computer Engineering Department,

Faculty of Engineering, Campus #2
University of Tehran
Kargar Shomali St. (Passed the Jalal-Al-Ahmad St.,
Across the Ninth Lane)
Tehran, Iran

Tel : +98 21 8020403   Ext.3545