Blisters

About: Blisters is a research topic. Over the lifetime, 980 publications have been published within this topic receiving 16229 citations.

Hydrogen blister depth in boron and hydrogen coimplanted n-type silicon

Abstract: We have studied the depths of hydrogen surface blisters in 〈100〉 n-type silicon, which formed after B+H coimplantation and heat treatment. The silicon substrates had three different dopant levels, ranging from 1014 to 1019 cm−3. The Si substrates were first implanted with B+ ions at 147 keV to a dose of 1015 cm−2. Some of the B-implanted samples were left in their as-implanted state; others were electrically activated by a rapid thermal anneal. The samples were then implanted with 40 keV H+ to a dose of 5×1016 cm−2. At the chosen implantation energies, the hydrogen- and boron-implantation distributions overlap. Following H+ implantation, all the samples were vacuum annealed and examined by ion-beam analysis and scanning electron microscopy. In all cases, the blister depth was consistently found to be strongly correlated with the H damage profile rather than the H or B concentration profiles.

Development of a Synthetic Skin Simulant Platform for the Investigation of Dermal Blistering Mechanics

Abstract: Excessive frictional loading to the skin often results in the formation of blisters, due to the transmission of shear loading to the interfaces between dermal cell strata. The consequences of blistering range from mild discomfort to serious infection. In some patients, such as those disposed to epidermolysis bullosa or neuropathic diabetes, blisters can severely degrade life quality. Investigation of environmental and application parameters that affect blister formation has occurred primarily as a qualitative, observational pursuit on human subjects, which has often led to confounding of data and lack of repeatability. The authors have developed a Synthetic Skin Simulant Platform (3SP) that reproduces the mechanical behavior of human skin when exposed to tribological loading. The platform is an assembled construct of bonded elastomeric layers that act as surrogates for the epidermis, basement membrane, dermis, and subdermal structure. Epidermal (top layer) materials are typically silicone or polyurethane films with a friction coefficient akin to human skin, while sublayers display mechanical properties similar to their anatomical analogs. Blistering is evident optically by examining the separation voids formed after applying shear loads to the epidermal layer. The 3SP has been used in a two-axis pin-on-flat tribometer with a stainless steel indenter to study the normal load and friction coefficients encountered at the onset of frictional blistering. The 3SP allows for modulation of friction coefficient, interfacial adhesion strength, and subdermal stiffness for investigation of blistering damage to various anatomical sites. Experimental results have been compared to human test data and have shown that the 3SP provides the potential to make significant advances with respect to skin tribology research.

Role of strain in the blistering of hydrogen-implanted silicon

Abstract: The authors investigated the physical mechanisms underlying blistering in hydrogen-implanted silicon by examining the correlation between implantation induced damage, strain distribution, and vacancy diffusion. Using Rutherford backscattering, scanning electron microscopy, and atomic force microscopy, they found that the depth of blisters coincided with that of maximum implantation damage. A model based on experimental results is presented showing the effect of tensile strain on the local diffusion of vacancies toward the depth of maximum damage, which promotes the nucleation and growth of platelets and ultimately blisters.