Automated Mechanical Exfoliation of MoS and MoTe Layers for 2D Materials Applications.

An automated technique is presented for mechanically exfoliating single-layer and few-layer transition metal dichalcogenides using controlled shear and normal forces imposed by a parallel plate rheometer. A thin sample that is removed from bulk MoS or MoTe is initially attached to the movable upper fixture of the rheometer using blue dicing tape while the lower base plate also has the same tape to capture and exfoliate samples when the two plates are brought into contact then separated. A step-and-repeat exfoliation process is initiated using a preprogrammed contact force and liftoff speed.

Effects of dimethylsulfoxide on the ultrastructure of fixed cells.

It has been reported that the use of dimethylsulfoxide (DMSO) as a solvent for fixatives enhances preservation of cellular ultrastructure. By contrast, we have shown that DMSO alters the ultrastructural integrity of glutaraldehyde fixed cells. The cell membrane, nuclear envelope, endoplasmic reticulum, ribosomes, microtubules and intracytoplasmic organelles are most susceptible to the action of DMSO.