This paper reports nanoscale thermal analysis on a polycrystalline energetic material using a heated atomic force microscope cantilever tip. The heated tip performs highly local melting, evaporation, and decomposition with modifications in the material from 100 nm to several micrometers.

We have developed a flow cell that allows culturing adherent cells as well as suspended cells in a stable, homogeneous, and low-shear force environment. The device features continuous medium supply and waste exchange. In this paper, a simple and fast protocol for device design, fabrication, and assembly (sealing) based on a poly(dimethylsiloxane) (PMDS)/glass slide hybrid structure is described. The cell culture system performance was monitored, and the effective shear force inside the culture well was also determined. By manipulating the device dimensions and volumetric flow rate, shear stress was controlled during experiments. Cell adhesion, growth, proliferation, and death over long-term culture periods were observed by microscopy. The growth of both endothelial and suspension cells in this device exhibited comparable characteristics to those of traditional approaches. The low-shear culture device significantly reduced shear stress encountered in microfluidic systems, allowing both adherent and suspended cells to be grown in a simple device.

Pentaerythritol tetranitrate (PETN) is a secondary energetic material generally used in initiators for industrial and government applications. Changes in the morphology and surface area of aging powders have been observed during aging, which can modify the initiability and performance. Here work is presented using two different techniques to determine kinetic and thermodynamic parameters of single crystal PETN. Atomic force microscopy is used for low-temperature analysis, while thermogravimetric analysis is used at higher temperatures. A mechanism is proposed to expand the understanding of coarsening observed in real world PETN.

Atomic force microscopy (AFM) has been successfully used to study the activation energy for evaporation of pentaerythritol tetranitrate (PETN) nanoislands formed by spin coating. These islands are annealed isothermally in the temperature range of 30-70 degrees C for a given time and are scanned with AFM in contact mode at room temperature. The volume of these islands does not change significantly up to about 35-40 degrees C indicating that sublimation is not significant below 40 degrees C. Above 40 degrees C, the islands start shrinking, and the rate of weight loss is analyzed as a function of temperature. The activation energy of evaporation using AFM was found to be similar to that for bulk PETN crystals using thermogravimetric analysis (TGA) at higher temperatures (110-135 degrees C). These results demonstrate that AFM is a useful tool to measure thermodynamic properties with a nanoscale probe.