Researchers at the University of California, Davis, have developed a novel and high throughput production process of making nano/submicro-sized fibers.  By extruding in-situ micro or submicrofibrillar blend of cellulose acetate butyrate (CAB) and  polymers (polyolefin, polyesters, and proteins) into regular size fibers, CAB serves as a sacrificial matrix and other polymers as micro/nano-fibrills in the matrix in coarse fiber form. After removal of CAB with acetone extraction, micro, as well as, submicro fibers can be produced. (more...)

Lightweight armor materials have been developed that are damage tolerant and capable of defeating rifle-fired, armor-piercing rounds of ammunition. These materials are ideal for use as aircraft, watercraft and vehicle armor and have applications in both military and civilian arenas. In addition to being lightweight, the materials have a unique combination of hardness and toughness while being inherently damage-tolerant due to their novel structure. The process for creating the materials is inexpensive, simple to perform and control, and uses readily available components. The microstructure and mechanical properties of the materials have been characterized and preliminary prototype testing has been performed. Due to the low cost of the processing technique and the properties that can be created, the range of additional applications for this technology is large, including missile nose cones, aircraft components, vehicle structural components, gas turbine engine components and engine afterburner nozzles. (more...)

Suspended structures enable control of p-n or n-p-n junctions- the interfaces between diodes, transistors and other semi-conductor devices. However, fabrication of suspended structures using most current techniques is extremely difficult because direct deposition of dielectrics (or ‘insulators’) can stress or even collapse the thin graphene layers employed in these devices. UC researchers have developed a novel technique for fabrication of suspended structures on graphene (Figure 1). The UC technique makes it easier to fabricate a suspended top gate over the semi-conductor substrate and back gate. The top gate makes it easier to apply local electric fields that enhance mobility in graphene p-n and n-p-n junctions.     Figure 1: Suspended          top gate structures on graphene    The UC technique offers the following advantages relative to existing techniques: It is compatible with large-scale CMOS technology It utilizes air or vacuum as the dielectric rather than solid materials. This eliminates current leakage, a recurring problem in most currently fabricated CMOS devices Ease of deposition of suspended top gate eliminates unintentional damage to graphene Fabrication in only one vacuum cycle vastly reduces manufacturing costs   The UC technique ensures that the graphene devices formed do not suffer from undesirable defects that arise from deposition of intervening layers that involve introduction of impurities and dopants. The technique does not require etching of sacrificial (or ‘resist’) layers, which may inadvertently edge other components during fabrication.   The new UC technique can also be applied to fabrication of other types of devices that are highly sensitive to process-induced damage. These devices may include sensors for detection of local magnetic fields and micro-electrochemical (MEM) devices with moving parts such as resonators.   The UC technique can also be used to induce local magnetic fields, which can be employed in conjunction with magnetic media for data storage. The localization of magnetic fields eliminates the need for a read/write head that moves over the surface of the magnetic media. The use of high density array of suspended structures using the UC technique may result in production of high density magnetic storage devices. (more...)

Production of Micro- or Sub-Micro Sized Polypropylene-Biocidal Fibers through Reactive Spinning of Synthetic Fibers (more...)