A novel method to satisfy the need for growing large non-polar and semi-polar substrates.   (more...)

A novel method for ammonothermal growth of group-III nitrides using natural convection.   (more...)

A strategy to the design of dispersing agents with the favorable interactions of polymeric dispersants and the specificity and high binding strength of small molecules.  (more...)

Sintering of metallic nanopowders at lower temperatures, times and/or pressures during parts manufacturing. (more...)

Dehumidifier and condenser applications (where water is condensed onto a chilled surface) are common in power plants, desalination plants, chillers and heat exchangers. In these applications, condensation can be enhanced with an alternating hydrophilic-hydrophobic pattern on the condensation surface. This patterning has been implemented using polymers, self-assembled monolayers and other non-conducting materials. These approaches create chemically heterogeneous surfaces that have limited lifetimes -- due to the thickness and durability of the film.To address this situation, researchers at UC Berkeley have developed a surface with alternating hydrophilic-hydrophobic patterning that promote dual and simultaneous modes of condensation -- filmwise and sustained dropwise condensation -- on a chemically homogenous conducting material (metal substrate) -- which is the material of choice for condenser applications. This innovation is achieved with a practical and scalable technique of surface machining or roughening based on the preferred dimensions of the pattern. The resulting chemically homogenous, conductive substrate is important for maintaining a substrate with high thermal conductivity and doesn't add any thermal resistance that would impede the condensation heat transfer.   (more...)

This invention is a new process to create microlens arrays and microwells in plastic.Microlenses are primarily fabricated from glass and optical grade polymers. One such plastic is polystyrene (PS), which has a high index of refraction, high optical transmission, and spectral band pass. Glass microlens array production is comparatively older but polymers have been favored for their affordability and ease of manufacture as well as the ability to control their thermal and mechanical properties. Previous methods for polymer arrays include: photoresist reflow, microjet printing, and direct laser writing. High temperature reflow of photoresist to create such rounded high aspect ratio structures is difficult and often results in rather shallow lenses. Then, to transfer the patterns into hard plastics via hot embossing, costly and slow electroplating is required. Instead, we created our molds using a laser jet printer and a technique which solves the shortcomings of modern manufacturing techniques. We address the issue of microfabricating high aspect ratio structures with high curvature (deep and round). Reflow of photoresist, the common way to make such structures typically results in shallow radii of curvature structures. Moreover, to transfer such structures to hard plastics typically require hot embossing, which requires a metallized (e.g. nickel electroplated) mold. This is very slow and expensive. Our technique allows our masters to be created with a laserjet printer. Then we can do soft lithography to transfer this to PDMS. Finally, we use the PDMS mold for the hot embossing back into a thermoplastic sheet. One problem solved by plastic microwells is the culturing of embryoid bodies (EB). EBs require size, morphology, uniformity and reproducibility control. Previous methods often required a trade-off between quantity and uniformity. PDMS microwells were a great improvement and did much to address these concerns. PDMS have the drawbacks of non-selective absorption, swelling, and poor mechanicalproperties. Polymer microlens arrays have been seen to have much potential but popular techniques for fabrication have various problems. For example,photoresist reflow suffers from chemical and thermal instability, has high requirements for consistency and reproducibility, and need photosensitive material. Some such disadvantages have been overcome but very often require expensive equipment and a time consuming process. This is new method of creating features on the microscale. The inverse of features previously formed in polydimethylsiloxane (PDMS) is transferred to a thermoplastic such as prestressed polystyrene. This is performed by placing the thermoplastic on the PDMS mold, forcing the substrates towards one another through uniform pressure, and baking them past the glass transition temperature of the thermoplastic. Inherent in this process are the multitude of techniques to pattern in PDMS and the ability of thermoplastics to become malleable when properly heated. The purpose of this is to create microstructures that may be used in various applications such as embryoid body culture or optical communication and interconnection. To demonstrate ability of the microlens arrays, we conducted a simple laser experiment was performed. As the laser was shown through the 460 um microlens array a z-stack of images were acquired. Using this information the numerical aperture for several lens were calculated to approximately 0.14. With this demonstration the functionality of this new microlens array design has been proven. This new, inexpensive and relatively simple method to fabricate microlens arrays in a hard plastic with excellent optical properties can provide a platform for optical applications. (more...)

Heat reflective coatings represent an important tool in the energy management of any building. Unfortunately these coatings are usually expensive and sometimes even toxic, thus increasing their production and application costs. Researchers from UCI’s Chemical Engineering and Material Science Department have developed a new class of energy efficient coatings consisting of a material that is derived from a naturally occurring and inexpensive biomolecule. This invention represents a novel heat reflective coating, which can be readily produced in large quantities at a very low cost. Moreover, the coating is fully biocompatible, further reducing total life cycle costs at both the production and installation stages, as well as the removal/replacement stages. (more...)

Nitrogen-rich tetrazines, have broad applications in biochemistry including small-molecule imaging, genetically targeted protein tagging, post-synthetic DNA labeling, nanoparticle-based clinical diagnostics, in-vivo imaging, as well as significant use in materials science, coordination chemistry, and the production of high energy materials such as those used in specialty explosives research. Among other uses, tetrazines can serve as coupling agents for molecular imaging compounds such as fluorophores or magnetic contrast agents, or even as ligands for metal catalysts or inorganic materials such as metal-organic frameworks. Tetrazines are also valuable synthetic intermediates, and have been elegantly deployed on route to several natural product syntheses. Despite the promise of tetrazines, the lack of convenient synthetic methods is a significant roadblock to their broader use and study. (more...)

A method for photoelectrochemical etching of laser facets. (more...)

A bipolar transistor through a mechanism based on spin polarization. (more...)

Researchers at the University of California, Davis campus and the University of Missouri have developed a process for enhancing the superplasticity of metal and forming shapes from the metal. (more...)

A novel approach to create molds for manufacturing that allows for reusable molds that can be made into any arbitrary shape. (more...)

A novel living radical polymerization with highly responsive control over the activation and deactivation of polymerization using visible light as a trigger.  (more...)

Most of the contact lenses on the market today are made of rigid gas permeable plastics (RGP), hydrogels, or composite silicone-hydrogel materials. An essential property of all contact lenses is sufficient access of the non-vascularized cornea to atmospheric oxygen, a requirement for the health of eyes while wearing contact lens. Contact lenses are normally worn either on the eye cornea (more common, small corneal lenses) or sclera (less common, large size scleral lenses). Scleral contact lenses are more expensive, but have several advantages and are exclusively prescribed to people with certain eye disorders. Scleral lenses are normally machined from rigid gas permeable plastics, whose oxygen permeability practically limits lens thickness to ~0.5 mm. Nevertheless, there are some applications, for which it may be desirable to have scleral lenses of substantially greater thickness, and no rigid optical-grade materials with sufficient oxygen permeability is available for this task at present. (more...)

The IFMAR technology involves a catalytic bed reactor that utilizes a novel support network structure to immobilize catalyst particles for use in a wide variety of automotive and industrial process applications including exhaust gas treatment, hepa filter technology, gas masks, fugitive gas leaks from valves and fittings, etc. The catalyst particles and support particles are formed together as a binary, free molecule aerosol, whose size and morphology can be controlled by a systematic variation of the processing conditions. The immobilization of catalyst particles and support particles from a free molecule aerosol provides a reactor bed which optimizes catalytic interaction and activity while at the same time reducing the required pressure drop across the bed.  This highly efficient, compact, lightweight and portable construction answers the needs of industry that conventional units cannot meet because of size and efficiency restrictions. Further, the enhanced effectiveness of the invention will allow the use of lesser amounts of expensive catalyst materials than used by conventional catalytic systems. Because the total mass of support and catalyst is substantially smaller, the heat capacity of the converter would be low. The consequent decrease in warm-up time would be markedly reduced and could eliminate the "cold-start" problems of currently available technology. (more...)

A novel device and technique for the measurement of the rheological properties of fluid interfaces. (more...)

A novel process for the development of a rod-coil block copolymer containing a carbon-60 derivative that exclusively forms a nanofibrilar structure. (more...)

A fuel cell membrane that can sustain high and stable conductivity at temperatures above 150°C without requiring additional humidification systems or hydrating water.  (more...)

A blue electroluminescent material based on a binaphtyl compound. (more...)

A class of proton conducting membranes utilized as a major component of a polymer electrolyte fuel cell. (more...)

A novel process to create nanoparticle-embedded hollow cerium oxide spheres using less expensive metals than are typically used.  This cerium oxide nanoparticle complex remains stable at much higher temperatures than typical metal nanoparticles. (more...)

An ammonothermal growth method for high-quality group III-nitride bulk crystals at commercially practical growth rates. (more...)

Yellow-emitting phosphors, for fabrication of white LEDs. (more...)

A novel composition for electron injection layers applicable in PLEDs. (more...)

A composition for a zwitterionic catalyst applicable to olefin polymerization. (more...)

A novel method for the production of emulsions and dispersions, directed to methods for the formation of colloidal suspensions. These suspensions are formed with or without mechanical action and without surfactants, polymers, or stabilizing agents. (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...)

An integrated process has been developed for creating and bonding a hard, wear-and corrosion-resistant surface onto metallic substrates such as titanium, nickel or iron-based alloys. Surface layers that are orders of magnitude thicker than those obtained conventionally can readily be achieved and both the thickness and hardness of the surface can be tailored to specific applications. The process does not require vacuum or non-atmospheric environments and utilizes off-the-shelf components thereby making it easier and less expensive to perform than standard techniques. This novel, highly adaptable process has multiple applications, for example providing a viable way to apply wear-resistant coating to the titanium used in friction settings. (more...)

As part of the Tacky Dot® donation, the University is offering for commercialization an improved method for mounting particles on a substrate having both tacky and non-tacky areas using a direct current potential This invention especially has utility for the handling and transfer of solder balls and other conductive particles to form solder bumps on the contact pads of electronic devices. (more...)

Using the Tacky Dot® technology, University researchers have adapted the technology to the area of dry-screening phosphor displays which greatly reduces toxic decomposition products. The technology uses a powder of phosphor particles in a dry process using just a few steps to produce a phosphor pattern, including steps for the removal of excess charge and powder. This method removes the need for the use of a flux found in wet methods, and does not rely on spin coating or phosphor-specific adhesives (as found in earlier photo-tacky dusting methods). And unlike earlier methods that produce corrosive and toxic gases during decomposition, the research results using this method has uncovered no toxic decomposition products. This method is capable of producing phosphor patterns whose size is just a few microns. (more...)

This invention describes a novel laser device material based on an organic/inorganic hybrid glass that shows an unconventional optical phenomena of acoustically coupled Photorefraction. (more...)

Detecting ultra trace explosive analytes is important for forensic or counterterrorism  applications as well as for personnel, baggage, or cargo screening.  However, metal detectors frequently fail to detect explosives (such as those in the plastic casing of modern land mines); dogs are expensive and difficult to maintain: and other methods, including gas chromatography coupled with mass spectrometry, surface-enhanced Raman, energy dispersive X-ray diffraction, for example, are highly selective, but are expensive and not easily adapted to a small, low-power package.  Therefore, chemical sensors are preferable to other detection devices. (more...)

Synthesis of organic molecules plays a vital role in modern society: carbon-carbon and carbon heteroatom bonds are encountered in natural products, materials, drug substances and agrochemicals. There are currently methods in place for coupling phenol groups to carbon atoms, but these reactions require expensive materials and are often not efficient. Practical methods that allow for the cross coupling of phenol derivatives to carbon atoms are therefore extremely interesting, especially given their prevalence in the pharmaceutical industry. (more...)

In the race for achieving miniaturization of useful machines and devices to the microscale and nanoscale, it would be useful to have a means of connecting components to build devices. One-off production of assemblies of components might be made using laser tweezers or microfluidics, yet it would be highly desirable to assemble millions or billions of copies of the same multicomponent device in solution in parallel at the same time. Heretofore, such massively parallel off-chip assembly processes have been only poorly controlled because the interactions have not been strongly dependent on the nature of the geometry and shape of the components. (more...)

Bottom-up synthesis can produce a very limited variety of particle shapes, such as spheres and rods, in a viscous liquid. The resulting particles can be highly uniform in size. However, there is no general method for mass-producing a wide variety of highly complex shapes that are specified by a customer using bottom-up self-assembly approaches. Although uniform microspheres have been used extensively in many protocols, these applications can be enhanced by using particles that have customized, user-specified shapes. Mass-producing particle shapes that conform with a desired design would revolutionize the variety of dispersions that are commercially available. (more...)

In the push towards biofuels and biodegradable products, efficient growth within plant-based substrates will become more prevalent. Using a new strain design method, UC San Diego inventors have invented a new strain of E. coli that experiences high levels of glucose uptake fermentatively relative to other known strains with a weight yield of 98.4 ± 3.4 percent and with an uptake rate of 43.1 ± 1.3 mmol gDW-1 hr-1. An additional advantage is the strain’s ability to uptake xylose (though not at the same high rate). The utility of this new strain is in higher rate fermentation processes. The increase in the uptake of glucose potentially provides an increase in the production rate of D-lactic acid or other desired compounds. The production of D-lactic acid is a pre-cursor step to the production of biodegradable plastics (i.e. polylactic acid). The research leading up to this invention is described in papers located at http://gcrg.ucsd.edu/Researchers/Feist_Publications. The design methodology for this strain can also be applied to produce other strains with other attractive properties. (more...)

Emulsions are commonly used in food products, cosmetics, paint, etc. Polymer microspheres have applications in, for example, drug delivery and tissue engineering. A challenge in creating polymer microspheres and emulsions is minimizing the polydispersity of the particles. The particles tend to have inconsistent size, shape and mass distribution. Silk is often used commercially as an emulsion, and has been demonstrated to be an extremely effective polymer for drug delivery. Microfluidic devices that produce microsphere have been demonstrated in the past. However, it has been difficult to produce particles with a consistent size and shape known as monodisperse particles. Researchers at UC Berkeley have developed a microfluidic methodology for producing monodisperse silk microspheres. The unique chemistry and method enables production of exact microsphere diameter and percent of crystallinity. Both the microsphere and crystallinity can be precisely adjusted which can be used in for a variety of applications. It is particularly useful to vary drug release characteristics in a drug delivery system. (more...)

There are presently many examples of 1-, 2-, and 3-dimensional objects constructed using so-called self-assembly reactions. For example, covalent bonds formed between alkanethiols and gold substrates have been used to pattern surfaces; or hydrogen bonding interactions between DNA base pairs have been used to assemble nanoparticles into complex assemblies. Researchers at UC San Diego have developed a novel technique that allows for the production of optical films with spatially resolved, chemically-distinct layers. Although there is literature precedent for a range of surface modifications on porous silicon, the method can dually functionalize the sensors that impart to them their ability to self-assemble and orient selectively at an interface. The main requirement of the chemical modification reaction used in the functionalization steps is that they be stable to the hydrofluoric etchant used in generating subsequent porous silicon layers. It is anticipated that a number of chemical and electrochemical modification strategies developed for porous silicon can be used with this procedure. (more...)

An extremely versatile drug delivery system composed by a lipid-bilayer vesicle. (more...)

In a vacuum, light propagates with a constant velocity, while in an optically transparent non-dispersive media, the speed of light propagation can be different. At optical frequencies, the refractive index of transparent materials usually does not exceed several units, and the speed of light propagation is of the same order of magnitude as the speed of light in vacuum.The situation can change dramatically in strongly dispersive media. Although the phase velocity of light is still determined by the same mathematical expression, the speed of electromagnetic pulse propagation is now different and is determined by the group velocity which is one of the most important electromagnetic characteristics of the medium. With certain reservations, the group velocity coincides with the electromagnetic energy velocity and is usually referred to simply as the propagation speed of light in the medium.Strong dispersion means that the group velocity strongly depends on the frequency. In the slow light case, the electromagnetic pulse propagates through the dispersive medium at a speed, regardless of the respective value of the phase velocity. In some cases, it can even turn virtually to zero, which implies that the electromagnetic wave at the respective frequency does not transfer the energy.Slow and ultraslow light can have numerous and diverse practical applications. These phenomena can be associated with dramatic enhancement of nonlinear effects (higher harmonic generation, wave mixing, etc.), magnetic Faraday rotation, and many other important electromagnetic properties of the light-conducting medium. Such an enhancement can facilitate design of controllable optical delay lines, phase shifters, miniature and efficient optical amplifiers and lasers, etc. In addition, ultraslow light might allow nonlinear interactions down to a single photon level. (more...)

Large scale confinement chambers have been created in the past using traditional glass-blowing techniques. However, conventional glass-blowing can only be used to create large components and requires the components to be made one at a time. Micro-glass spheres have previously been fabricated by letting glass particles fall through a temperature-controlled drop tower. While it is possible to create hollow spheres by introducing a blowing agent in the glass, these micro-spheres are not attached to a substrate and are therefore difficult to integrate with micro-machined components on a wafer. (more...)

Currently, X-ray mammography is the widely accepted method for the detection of changes in the breast that may be cancer. However, this screening technique lacks specificity to determine whether detected abnormalities are either benign or malignant. A significant number of suspicious masses referred by mammography for surgical biopsy are in fact, found to be benign. These false-positive mammograms may cause patient anxiety and lead to increase healthcare costs. (more...)

This invention uses previously known chemical compounds for a new purpose - controlling mosquitoes in their aquatic larval stage. Preliminary results indicate that the compounds are also active against the other aquatic forms of mosquito (i.e., the eggs and pupae). (more...)

In order to improve energy utilization and correspondingly lower energy use and cost, there is growing interest in improving the intelligence of the electricity grid, and in particular, improving the intelligence of the vast infrastructure of power distribution cables. To address this need, researchers at UC Berkeley have developed an innovative way to measure the applied operating voltage inside conventional AC high-voltage insulated power distribution cables. The novel approach measures voltage non-conductively using a sensor that is external to and in proximity with the cables. The voltage sensor can be self powered via energy scavenging, and it can be readily coupled to a wireless network for data transmission and collection. (more...)

UC Berkeley researchers have previously presented a unique label-free method to detect biomolecular binding based on impedance changes using microparticles or nanoparticles in microfluidic channels. This method requires no florescent labeling of analyte and allows a simple readout at a given frequency. This demonstrated microfluidic integration of the nanocavity system is also advantageous, allowing easy introduction of analyte solution and measurement buffer. Because the detection technique is essentially label-free and just depends on the specific binding of anibody-antigen, DNA-DNA, DNA-RNA, DNA-protein, antibody-small molecule, or antibody-cell, this invention could be used to diagnose virtually any disease. Researchers at UC Berkeley have expanded upon this innovation to demonstrate the ability to sequentially load different sized and different types of beads into a microfluidic channel. This has numerous applications, including the ability to successively capture smaller and smaller beads that otherwise would be impossible to capture. In addition, the cells can be mechanically lysed. (more...)

Berkeley Lab and UC Berkeley researchers have invented a plastic microfluidic chip with integrated interconnects. The researchers use inventive mold-making and injection molding processes to fabricate disposable chips with integrated ports that accommodate commercially available male fittings and can withstand pressures over 35 MPa. The ability to perform at these pressures enables the inclusion of porous materials inside the chip channels to increase surface area and provide functionalization, an ability that previously has been limited by interconnect reliability. Monolithic integration of the ports also eliminates the need for extra fabrication steps and contaminating bonding agents. The novel chip is injection molded as two parts and then thermal fusion or solvent vapor bonded. The inventors have optimized the parameters of the processes to maintain channel shape and ensure a strong bond, achieving low standard deviations in a series of fabrications. The ports have ANSI-standard internal threads to allow a high-pressure reversible fluid connection between micrometer-scale capillaries and the chip ? a connection that facilitates replacement of capillaries damaged at the capillary/chip junction. The ability to accommodate standard fittings also allows users to easily connect the chip channels with commercially available chromatography equipment. The designs are fabricated from a plastic with low background florescence, which enables the use of laser induced fluorescence (LIF), a very sensitive detection technique. The material's high transmission to ultraviolet (UV) and deep-UV light allows the channel walls to be patterned using UV light. (more...)

Cantilevers are commonly used in MEMS as simple sensor elements for transducing environmental stimuli. However, a key challenge in using cantilevers for sensing is maximizing their sensitivity, and that is typically determined by geometry, materials and energy coupling. To improve sensor sensitivity, researchers at UC Berkeley have developed a cantilever design with a high coefficient of thermal expansion mismatch that increases beam bending for a given amount of input energy. Furthermore, the Berkeley researchers have incorporated novel materials for infared absorption such that the coupled energy is related to the spectral absorption. This approach differs from the broadband response of conventional thermal detectors. (more...)

Testing and characterization of electrochemical energy cells such as microbatteries is critical in the development of battery-powered microelectronics. Discharge and cycle testing of microbatteries may require days or weeks of continuous monitoring, and often must be conducted in a closed environment such as a glovebox. Galvanostatic studies are at present the preferred method for characterizing the performance of energy cells, but characterization of microbattery performance requires galvanostats with microamp or better resolution. Commercially available galvanostats are capable of testing multiple cells in parallel, but instruments with the required microamp resolution are bulky, cost at least $1000 per channel, and must be hard-wired to each test cell. Higher resolution instruments cost from $5000 to $10,000 per channel?prohibitively expensive for many testing facilities. Commercial galvanostats are also useful for testing and characterizing fuel cells and for electrodeposition studies and corrosion measurement, and while resolution is not a cost driver, instruments for these applications are also large and expensive, and have limited scalability. Researchers at the University of California, Berkeley have developed a wireless galvanostat device with nanoamp resolution. The device supplies a programmable constant current anywhere from 1 nanoamp to 15 milliamps. The device is preferable to conventional galvanostats for applications such as battery and capacitor development, and for corrosion or electrodeposition studies, where testing in a usage environment and cost per channel are critical factors. The unit is small, battery powered, and transmits all data wirelessly to a computer, allowing for quick and easy placement in an inert atmosphere, such as a glove box or deposition chamber. Fabrication cost of Berkeley?s wireless galvanostat is less than $100 per channel, even without factoring in economies of scale. (more...)

Patterning of biomolecules is important in areas like biological analysis, diagnostics and genomics. In addition, molecular patterning could be useful for spatial control of various surface properties such as hydrophobicity and surface charge. Currently, molecules are patterned using lithography, stamping, or using scanning tips. Lithography requires either specially synthesized light-sensitive molecules or exposure to developing solutions for photoresists, which are usually incompatible with sensitive molecules. The other two processes involve a mechanical transfer of molecules between a stamp or a scanning tip and the surface to be patterned and are therefore highly sensitive to surface tension, transport on the tip and other surface phenomena. These techniques also require specialized scanning tips or alignment equipment. While these techniques are useful for patterning two-dimensional patterns on surfaces with sub-micron resolution, no technique exists for patterning within confined regions such as small microchannels or nanochannels. Researchers at UC Berkeley have developed a new technique for patterning molecules that is compatible with sensitive molecules and can be used in confined areas. The process can be used for applications in microfluidics and nanofluidics, where patterning using other techniques is not possible. The method is also useful for patterning of surface properties such as surface charge. Other applications include patterning biomolecules such as antibodies inside of nanopipettes and patterning sensitive biomolecules on flat surfaces. (more...)

Piezoelectric bending actuators have the potential to be used as the muscles in a variety of autonomous, micro-mechanical robotics devices under development. While commercially available bending actuators have the requisite high levels of mechanical energy for these miniature robotics applications, the mass of these existing actuators are too high -- by orders of magnitude. To address this problem, researchers at UC Berkeley have developed a new class of piezoelectric bending actuators with ultra-high energy densities. These new actuators have been optimized for low-mass applications using sophisticated math models, and their benefits are based a variety of innovative design features and fabrication methods. The actuators can be tailored for most kinematic and dynamic requirements. Whereas commercial piezoelectric bending actuators have energy densities that range from 0.15 to 0.007 Jkg(-1), and masses that range from 340 to 120,00 mg, a bimorph version of this new class of actuators exhibited an energy density of 2.5 Jkg(-1) with a mass of just 11 mg. (more...)

Broadband mirrors with very high reflectivity are essential for applications such as telecommunications, surveillance, sensors and imaging. Among the various conventional mirror designs, metal mirrors have larger reflection bandwidths but lower reflectivities; as a result they are not suitable for fabricating transmission-type optical devices such as etalon filters. Dielectric distributed Bragg reflectors (DBRs) can achieve a higher reflectivity but deposition methods for DBRs are often not precise enough to yield the reflectivities of 99% or better needed for demanding applications, and typical material combinations constrain the mirror bandwidth and can be incompatible with conventional semiconductor processing technologies. In addition the tuning range is often limited for tunable etalon type devices such as MEM vertical cavity surface emitting lasers (VCSELs), filters, and detectors. There is a need for a mirror with broadband reflection, low loss, and compatibility with conventional optoelectronic processing methods. Researchers at the UC Berkeley have developed a single layer, sub-wavelength grating with a very broad reflection spectrum and very high reflectivity. The grating design facilitates monolithic integration of optoelectronic devices at a wide range of wavelengths from visible to far infrared, as well as integration with electronic circuits and other optoelectronic devices. Grating spectral characteristics can be tailored by choice of materials and structure to maximize both reflectivity and spectral coverage. The grating design developed at Berkeley has potential application in MEM tunable devices and reconfigurable focal plane arrays for such high value applications as optical communications, chemical/biological sensors, and imaging. (more...)

The objective of molecular imprinting is to create solid materials containing chemical functionalities that are spatially organized by interactions with imprint (or template) molecules during the synthesis process. Subsequent removal of the imprint molecules leaves behind designed sites for the recognition of small molecules, making the material ideally suited for applications such as separations, chemical sensing and catalysis. A significant limitation to the use of bulk imprinted silica in catalytic applications has been due to the hydrophobic framework resulting from the materials synthesis process. Researchers at the University of California, Berkeley have developed a process for synthesizing a new class of bulk imprinted silicates with a hydrophilic framework, which circumvents these limitations. Imprinted sites consisting of up to two primary amines have been synthesized within hydrophilic microporous and mesoporous inorganic-oxide frameworks. The preparation of bulk-imprinted silicas is a step toward the development of imprinting as a general strategy for synthesizing materials-by-design. (more...)

Researchers at the University of California, Berkeley have developed an apparatus for manipulating micro-scale objects. At the micro-scale level, adhesion forces of surface tension, and electrostatic and Van der Waals force dominate gravitational forces. Recent work has shown how adhesive forces can be used advantageously during microassembly tasks by controlling contact areas and surface tension, to ensure that microparts are reliably transferred to the target surface and released from a gripper. (more...)

United States Patent 6,359,174 MacMillan , et al. March 19, 2002 ------------------------------------------------------------------------ Lewis acid-catalyzed claisen rearrangement in the preparation of chiral products Abstract A novel Claisen rearrangement reaction is provided. An allylic reactant such as an allylic amine, an allylic ether or an allylic thioether is reacted with an acid chloride in the presence of a Lewis acid catalyst composition composed of a Lewis acid and a base selected from the group consisting of tertiary amines and non-nitrogenous bases. The stereochemistry of the reaction product is readily controlled by the positioning and size of substituents on the allylic reactant. The reaction may be carried out on a solid support, i.e., on the surface of a substrate suitable for conducting solid phase chemical reactions. (more...)

The manufacture and miniaturization of integrated circuit components has made possible the operation of microprocessors at gigahertz frequencies as well as achieving gigabit capacities in dynamic random access memory (DRAM). However, one of the main future limitations for this technology is the inability to continue scaling the photolithographic techniques currently employed in complementary metal oxide semiconductor (CMOS) transistors. Block Copolymer (BCP) lithography is currently one of the most promising techniques to achieve the desired miniaturization, however, no long-range ordering has been achieved in thin film mixtures of two chemically dissimilar block copolymers, because such mixtures tend to exhibit macrophase separation. (more...)

A novel adhesive system able to stick and unstick controllably. (more...)

Researchers at UCSB have developed a new synthetic process that creates novel semiconducting, photoconductive, photovoltaic, optoelectronic and battery thin films and materials at low cost. This new process has many distinct advantages over the current state-of-the-art, including: low cost, low energy, room-temperature synthesis; production of high quality single crystal sheets of material with low resistivity and high electrical connectively formed both on and off substrates; and, high flexibility within process to create wide spectrum of materials as well as to modify critical properties of the materials, such as layer thickness and the absorption spectrum. The new process uses a solution-based concerted reaction based on the hydrolytic catalysis of molecular precursors to create high purity materials at room temperature through spontaneous reactions. The process allows for directed growth and, because there is no addition of a molecular template to direct the growing crystal, a high purity material that is electrically continuous over a microscopic length scale without the need of further processing to remove organic or other contaminants. Ohmic contact is achieved without the need for annealing or alloying to a metallic conductor to make low resistivity electrical connections. The materials that result from this process can be transferred to, or formed upon, a number of flat conductive or insulating substrates and are compatible with the CMOS and other semiconductor nanofabrication methodologies. Additionally, the method allows the user to precisely tune the process to create tailored, unique materials in the size and quantity sufficient for incorporation into electronic, electrical and optoelectronic devices. The researchers have used this method both to develop new materials, such as a cobalt-based material, as well as materials currently used in manufacturing products in these areas. (more...)

Organic molecules that absorb two or more photons simultaneously have wide applications in a variety of technologies involving such subjects as optical data storage, 3-D microfabrication techniques, frequency upconverting lasing, optical power limiting, photodynamic therapy, initiators of polymerization reactions, and multi-photon fluorescence microscopy for biological imaging.   (more...)

Triplet emitters are promising materials for creating bright organic light emitting diodes (OLEDs). Iridium (Ir) organometallic complexes are especially attractive because of their high quantum yield of phosphorescence and their tunability over a broad emissive spectral range. However, at high carrier injection rates, saturation of emissive states and triplet-triplet quenching limits OLED performance. Thus, there is a need to accelerate Ir radiative decay in OLEDs while keeping other optical properties unperturbed. (more...)

Nanoparticles with very small diameters (<100 nm) can be produced from a variety of compositions, such as metals, metal oxides, metal non-oxides, and polymers. The physical, chemical, and electronic properties of nanoparticles differ from those of bulk materials and molecules, which makes them desirable for preparing macroscopic, functional materials and devices. Directed nanoparticle assembly requires highly specific interactions between nanoparticles and organic molecules to achieve controlled construction of the multidimensional nanostructures. Due to their encapsulation properties, hollow spheres provide an attractive structure for many applications. However, current preparation methods are labor-intensive and require multiple, sequential steps.   (more...)

A novel type of mesoscopically organized inorganic/organic block copolymer composites. (more...)

Combinatorial chemistry involves searching a large compositional space for compounds with a high figure of merit in order to find a molecule with a given property. However, current methods of searching only apply to relatively small libraries of compounds, with limited numbers of compositions and figures of merit that change smoothly with the composition. For example, exhaustive search methods fail when the potential composition space is larger than can be constructed or searched in a single library, and the genetic algorithm approach tends to fixate on local optima instead of finding the best set of molecules. (more...)

Silicatein filaments produced by a particular marine sponge that  have been shown to catalyze and spatially direct the in vitro polymerization of silica and silsesquioxanes from silicon tetraethoxide and organically modified silicon triethoxides, respectively, at neutral pH. (more...)

A modular, energy-dissipating material that prevents failure of adhesives, fibers and composite and other structures. (more...)

Gels based on high molecular weight polyethylene glycol (PEG) have been used for many biological applications because of their low immunogenicity. Conventional gels incorporate solid-phase components, constraining their manipulation and use in a variety of areas such as molecular drug delivery. Gels that can function without solid-phase components would help to overcome many of these difficulties. (more...)

A novel processing technique to prevent hydrogen incorporation. (more...)

Ceramic matrix composites (CMCs) contain strong, reinforcing fibers embedded in a ceramic matrix. CMCs exhibit superior toughness and strength and are especially tolerant of impact and thermal shock. The fabrication of current CMCs employs a third material to create a weak interaction between the fibers and the matrix. When cracks form within the matrix, they are deflected along the weak interface without propagating through the fibers. The fibers bridge the crack and enable the composite to continue supporting the load through the fibers. Current manufacturing methods are expensive and material systems are limited because it is difficult to create this weak interface and the current belief is that the density of the ceramic matrix must be high. In addition to manufacturing difficulties, current CMCs may exhibit bonding of the fibers to the matrix when the composite is used in oxidizing environments at moderate temperatures. This fiber-matrix bonding severely degrades the mechanical properties of the composite material. (more...)

Quantum dots possess unique properties that could potentially revolutionize existing optical and electronic technologies as well as open up new technologies. Conventional quantum dot fabrication techniques, however, have several drawbacks, such as large recombination velocities and surface depletion, that arise from having the surface exposed while patterning the substrate before or after growth. Researchers at the University of California have developed a quantum dot fabrication process that does not require any processing steps either before or after growth and so avoids typical problems such as surfaces, dislocations, and surface states. This process produces uniformly sized quantum dots in single or multiple layers out of any semiconductor, metal, or oxide material system that allows consecutive epitaxy and has lattice mismatch. (more...)

Transition metal carbides, nitrides and carbonitrides hold considerable commercial interest because of their properties of hardness, corrosion resistance and thermal stability. The manufacture of the whole class of materials has, however, remained cumbersome and costly up to now. The conventional synthesis of Titanium carbonitride involves three steps: Formation of a carbide phase, a nitride phase, and an homogenization of the two conducted at high temperatures over the course of several hours. Materials scientists at the University of California have recently developed a technique for the direct synthesis of titanium carbonitride. Their procedure takes place in a single, rapid step. Under the conditions of the procedure, a 2000 degree Celsius, self-sustaining combustion wave passes through and converts reactants at a velocity of 9 mm per second. Following propagation of the initial wave, the reaction is complete after approximately 1.7 seconds. The synthesis technique has all the attractive features of combustion syntheses in general, including straight-forwardness, high purity of products, and easy applicability to the manufacture of large items. UC investigators have submitted their products to X-ray analysis, and have found that the synthesis converts reactants completely to a single, cubic, NaCl-type crystal phase with lattice parameters of 0.4269-0.4309 nm. No other phases, by-products, or regions of nonhomogeneity appear in the reacted mixtures. The high temperature at which conversion to titanium carbonitride takes place indicates the high thermal stability of this material. A quality that has attracted additional attention to this particular transition-metal carbonitride is the affinity with which it conjugates with nickel. Titanium carbonitride/nickel cermets have the advantages of tungsten carbide/cobalt cermets but are considerably less costly to produce, given the low cost of nickel relative to cobalt. The development of a direct synthesis by UC researchers makes titanium carbonitride the most desirable material of its type. (more...)

A composition for a self-doped conducting polymer. These polymers are capable of decreased response times in doping operations and of maintaining a stable, doped state for longer than traditionally doped polymers. (more...)