Category Archives: LEDs

October 31, 2008: WaferGen Biosystems Inc., a developer of gene expression, genotyping, cell biology, and stem cell research systems, announced that the National Institutes of Health (NIH) has awarded a team of researchers at University of Pittsburgh a ~$3 million grant to conduct novel gene expression research in the area of lung disease involving WaferGen’s SmartChip Real-Time PCR System. This research team, led by Naftali Kaminski, Steven Shapiro, and Frank Sciurba, will apply gene expression profiling to lung samples from patients with chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

WaferGen’s SmartChip platform will be used to validate the researcher’s gene expression.

The SmartChip Real-Time PCR System provides a number of ease-of-use features including content-ready, high-density chips containing 30,000-100,000 nano-wells with gene panels optimized for cancer, toxicology and whole genome. The user-friendly SmartChip Real-Time PCR System will be preloaded with some of the reaction components. At the same time, the system will only require a very small sample size as compared to other technologies and platforms and will offer real-time detection and sophisticated read-out options while assuring detection sensitivity and temperature uniformity across chips.

Additionally, this NIH-funded research will include the development and application of the PulmoSmartChip, a custom designed SmartChip molecular phenotyping assay for COPD and IPF. The PulmoSmartChip, which will include the lowest number of genes that distinguish all phenotypes of IPF and COPD, will be used to identify and validate module networks capable of predicting the natural history of the diseases and patients’ response to specific therapeutics. Researchers at the University of Pittsburgh believe that the availability of these modules, as well as the validated PulmoSmartChip assay that allows their measurement using parallel quantitative real-time PCR, will be a significant step in laying the foundations for the introduction of personalized medicine approaches in pulmonary medicine.

“The decision by the NIH to fund this important gene expression research at the University of Pittsburgh represents a critical step for WaferGen and our SmartChip platform. We are pleased by the decision made by our collaborators at the University of Pittsburgh to involve the SmartChip Real- Time PCR System in novel gene expression research projects,” stated Alnoor Shivji, WaferGen’s chairman/CEO. “The work related to the development and use of the PulmoSmartChip is particularly exciting as it will seek to demonstrate the inherent power of the SmartChip system in creating and utilizing custom disease-specific gene expression assays. We anticipate that this cutting-edge functionality, which we believe is reproducible and applicable across all disease areas, will position the SmartChip system as the platform of choice for discovery and validation of biomarkers.”

October 31, 2008: Nanoparticles filled with small interfering RNA (siRNA) molecules targeting two genes that trigger melanoma have shown that they can inhibit the development of melanoma, the most dangerous type of skin cancer. The nanoparticles, administered in conjunction with ultrasound irradiation, exerted their effects only on malignant tissue, leaving healthy tissue alone.

“It is a very selective and targeted approach,” said Gavin Robertson, who led the team of researchers from the Penn State College of Medicine. “And unlike most other cancer drugs that inadvertently affect a bunch of proteins, we are able to knock out single genes.”

The Penn State researchers speculated that siRNA could turn off the two cancer-causing genes and potentially treat the deadly disease more effectively. “siRNA checks the expression of the two genes, which then lowers the abnormal levels of the cancer causing proteins in cells,” explained Robertson. This research appears in the journal Cancer Research.

When the researchers exposed lab-generated skin containing early cancerous lesions to the treatment 10 days after the skin was created, the siRNA reduced the ability of cells containing the mutant B-Raf to multiply by nearly 60%-70% and more than halved the size of lesions after three weeks.

“This is essentially human skin with human melanoma cells, which provides an accurate picture of how the drug is acting,” said Dr. Robertson.

Mice with melanoma that underwent the same treatment had their tumors shrink by nearly 30% when only the mutant B-Raf was targeted. There was no difference in the development of melanoma when the Akt3 gene alone was targeted, although existing tumors shrank by about 10%-15% in 2 weeks. However, when the researchers targeted both Akt3 and mutant B-Raf at the same time, they found that tumors in the mice shrank about 60%-70% more than when either gene was targeted alone.

“If you knock down each of these two genes separately, you are able to reduce tumor development somewhat,” Robertson said. “But knocking them down together leads to synergistic reduction of tumor development.”

This work, which was supported in part by the National Cancer Institute.

Oct. 30, 2008 – Thanks to the global economic shakiness, the SIA’s forecast of ~4.5% growth for 2008 is in jeopardy.

Chip sales in September inched up 1.1% to $23B, slowing from August’s 2.4% month/month increase, and were up just 1.6% from September 2007 (vs. 5.5% Y/Y last month). Through the first nine months of 2008, chip sales total $196.4B, about 4% higher than the same period a year ago. Excluding the still-suffering memory segment, chip sales rose 7.8% Y/Y in September, also slower than August’s 11.4% nonmemory growth.

Geographically, all regions lost ground compared with August’s Y/Y comparisons, led by North America where the Y/Y decline more than doubled (see chart below). The rolling three-month average actually improved overall, but that was solely due to a surge in Japan which completed its fiscal half-year, more than making up for continued slumps in North America.

The semiconductor industry now appears to be feeling the effects of world financial market turmoil, with near-term uncertainty weighed by “a steep decline in consumer confidence and caution in the enterprise market,” noted SIA president George Scalise, in a statement. He pointed to several ominous signs, including a 20-point drop in the Consumer Confidence Index to a new low. “Restoring consumer confidence is key to growing semiconductor sales going forward.”

Emerging markets remain a somewhat bright spot, though, he claimed, with sales of PCs and cell phones remaining strong in these regions, which are still enjoying mid- to high single-digit economic growth. Developing countries now account for nearly half of all unit sales of PCs, the SIA noted, and will account for nearly 70% of all cell phone unit sales this year.

Other semiconductor-demand apps remain promising, including MP3/PMP devices and LCD TVs, said the SIA, noting iSuppli projections of 11% and 33% growth, respectively, vs. ~5% growth for overall consumer electronics.

by Debra Vogler, Senior Technical Editor, Solid State Technology

Oct. 30, 2008 – TDI, an Oxford Instruments company, recently announced that it has developed a hydride vapor phase epitaxy (HVPE) technology that is based on a GaCl3-InCl3-NH3 system. The new process is able to control the growth rate of InGaN down to 1-2μm/hr and In content up to 43%. According to the company, HVPE is known for its capability to grow low-defect, crack-free, high-quality quasi bulk GaN and AlN materials at a significantly high growth rate of up to 100μm/hour.

The technique of X-ray diffraction reciprocal space mapping (RSM) was used to study the strain relaxation of the InGaN layers. TDI said its studies showed that low In-content InxGa1-xN (x~0.08 to 0.15) layers were either fully strained, or partially relaxed, with relaxation strongly depending on layer thickness and full relaxation for higher In-content layer (x~0.2 to 0.4). The results were recently presented at the Second International Symposium on Growth of III-Nitrides in Izu, Japan and the 2008 International Workshop on Nitride Semiconductors in Montreux, Switzerland. “This study further confirms the ability of HVPE to grow high-quality InGaN layers and extend its capability for blue-green LEDs production in the near future,” observed Alexander Syrkin, technology deputy director and team leader for the InGaN project at TDI.

The new process is of interest because green-blue-violet light emitters based on III-nitride compounds are typically fabricated utilizing InGaN alloys in the active region of optoelectronic devices. Most of these materials are grown by metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE).

Syrkin told SST that the particular structural characteristics of InGaN materials grown at TDI and cited in the presentations at IWN-2008 and ISGN-2008 represented the material parameters of the same level or exceeding those demonstrated by other methods. “The demonstration of InGaN materials with indium content in the range 10%-40% opens the opportunity to use this material both for the lattice-matched template substrate, reducing stress in the LED structure and for active regions of blue and green LEDs,” said Syrkin.

The high growth rate has been known since the HVPE technology’s introduction for III-V compound materials in the early 1960s, explained Syrkin. It’s defined by the thermodynamics, with the process usually held at atmospheric pressure and close to thermodynamic equilibrium; therefore, the efficiency of materials usage is higher than that for processes held at non-equilibrium conditions (e.g., MOCVD). “The use of atmospheric pressure also enables a higher concentration of active species participating in the growth (e.g. as compared to MBE also held at nearly thermodynamic equilibrium but in deep vacuum), thus creating a greater deposition rate,” he said. Due to lattice mismatch and the difference in thermal expansion coefficients between the substrate and the growing material, the latter tends to crack during the growth and thereafter. Higher growth rates therefore reduce cracking.


3D AFM image of the InGaN on GaN on sapphire layer surface, layer grown by HVPE. The scan area is 1×1μm2, the vertical scale is 5nm per division. (Source: TDI Inc., an Oxford Instruments company.
CLICK HERE to view larger image

How does the higher growth rate delivered by HVPE correlate with increased product quality? “It is well known that the defect density of material grown on foreign substrates (e.g., GaN on sapphire) decreases exponentially with the layer thickness, simply because the further away the growth face is from the foreign substrate, the less it is influenced by it,” Syrkin noted.

The company cannot fully disclose the mechanism responsible for the InGaN growth results, but Syrkin told SST that “it contains non-traditional approaches to the HVPE process.” No definitive answer has been discerned that can explain why the thin InGaN layers grown by HVPE can be either strained or relaxed, he added.

Because HVPE is a relatively straightforward process, it has a limited number of parameters that can be controlled and influenced, according to Syrkin. “TDI has, over the years, fully characterized each of these parameters, understood their influence on the growth process and the product quality,” he noted. “We have established the optimal operating conditions for runs of different material configurations and can repeatedly produce the same quality wafer to wafer within the run and between runs.”

The company also reported that its study on the growth of InGaN by HVPE was rewarded with substantial funding from a US government agency. — D.V.

(October 29, 2008) DURHAM, NC &#151Time flies when you’re having fun, or when you’re getting a start-up off the ground. From the introduction of an enabling technology, the thermal copper pillar bump (TCPB), through several rounds of funding, award of the North Carolina Green Business Grant, four product launches incorporating said technology, the construction and grand opening of a manufacturing facility, RoHS compliance, and ongoing plans for more, the past year has been peppered with notable events for Nextreme Thermal Solutions. Paul Magill, Ph.D., V.P of marketing and business development at Nextreme, talked to AP about the company’s philisophy and plans for the future.

“Cool what you need to cool, than manage it appropriately,” noted Magill, referring to Nextreme’s philosophy. From this premise, thermal management takes on new significance. Traditional cooling merely shifts heat to the next level without controlling it, whether it is away from the chip, package, board, system, and beyond. As the problem gets passed up, the solution cost does too. Unfortunately, as Magill explained, this ultimately leads to addressing the problem at the most expensive level. Therefore, by only cooling the part that needs to be cooled, heat abatement becomes much less of a problem at the next level. To illustrate his point, Magill cited energy consumption in data centers, where a fair amount of consumption is attributed to cooling the centers themselves. If these data centers applied Nextreme’s approach of cooling hot spots at the chip level with its TCPB technology, he noted, less energy would be required keep the room’s temperature at a level tolerable to humans.

The concept has caught on quickly. Nextreme first introduced the TCPB technology in October, 2007, and has integrated it successfully into several cooling and power generation devices. With the recent creation of the thermal management products business unit, headed up by Jim Mundell, the company intends to focus on thermal management products and aggressively engage with the telecommunications and photonics markets to enable the integration of the OptoCooler product line into optoelectronic devices.

The OptoCooler UPF4 and OptoCooler UPF40, for LED applications, pump heat at rates of .4 and 4 watts/cm2 respectively. Magill demonstrated how cooling the LED increases its light intensity, which translates to less power consumption and improved reliability. Further modifications included development of an array-based assembly process with bump sizes reduced by 75% to address telecom industry needs for higher voltage and lower current. The result is the recently launched OptoCooler HV14, which is a drop-in device that doesn’t require power conversion.

Additionally, Magill announced the company’s latest news that the OptoCooler UPF4 has been integrated successfully into Voxtel Inc.’s line of hermetically packaged avalanche photodiode (APD) receivers (Figure 1). Used for applications in military laser radar and optical communications and commercial telecommunications, the OptoCooler-equipped APDs reportedly offer improved efficiency, less noise, broader spectral and frequency response; improved overall gain, greater reliability, and a longer life span.

Figure 1: OptoCooler-equipped APDs. (Source: Nextreme)

“We are pleased that Voxtel has chosen Nextreme’s OptoCooler UPF4 for their thermal management solution.,” said Magill. “This represents further validation of our technology in a new application space and opens up a new channel for our OptoCooler product line.”

In addition to cooling applications, TCPB technology is also making inroads in power generation application as a thermoelectric generator (eTEG). When used in conjunction with a heat source and a heatsink the resulting temperature differential generates power. “eTEGs offer a way to convert waste heat into useful electrical energy,” explained Magill. Potential applications for the eTEG devices include powering gas sensor detectors on gas water heaters, or as include trickle charging of batteries for effluent sensors on smoke stacks.

October 21, 2008: The College of Nanoscale Science and Engineering (CNSE) of the University at Albany announced plans for the first celebration of “NANOvember,” a month-long series of events and activities that showcase the exciting world of nanotechnology and the global leadership of the UAlbany NanoCollege in the most important science of the 21st century.

Throughout NANOvember, a variety of activities are planned to engage students, teachers, parents and community members in nanotechnology — described by the National Nanotechnology Initiative as “leading to the next Industrial Revolution” — and to highlight CNSE’s educational program, ranked by Small Times magazine as number one in the world for nanotechnology, and its $4.5 billion Albany NanoTech Complex, an advanced research enterprise with more than 250 global corporate partners.

NANOvember kicks off with CNSE’s Community Day on Saturday, November 1, with a schedule of events that includes the unveiling of an exhibit in Colonie Center believed to be the nation’s first nanotechnology display in a shopping mall; hosting of a national conference on the convergence of nanobioscience and medicine; educational programs, such as “NanoCareer Day” for students and “Educating the Educators” for teachers; a series of community lectures highlighting CNSE’s pioneering education, cutting-edge research and significant economic impact; and, an open house for prospective graduate students.

NANOvember is presented as part of “NEXSTEP,” or “Nanotechnology Explorations for Science, Training and Education Promotion,” a partnership between CNSE and KeyBank featuring educational initiatives that promote greater understanding of the changing economic and business environment in the Capital Region and New York State being driven by nanotechnology.

“NANOvember is an exciting extension of the NEXSTEP initiative and its effort to help people understand the importance of nanotechnology and how and why nanotechnology is changing the Capital Region,” said Jeffrey Stone, president, Capital Region, KeyBank NA. “In the current economic landscape, this is a bright spot, as nanotech growth in our region, led by the UAlbany NanoCollege, will expand the tax base, attract more businesses and, most important, create more better-paying jobs.”


More than 300 elementary, middle- and high-school students got an inside look at the high-tech workplace of the future when they participated in NanoCareer Day held at CNSE in October, 2008.

October 13, 2008:Scientists from the London Centre for Nanotechnology (LCN) at University College London, are using a novel nanomechanical approach to investigate the workings of vancomycin, one of the few antibiotics that can be used to combat increasingly resistant infections such as MRSA. The work is discussed in the October 12, 2008 issue of Nature Nanotechnology.

The researchers, led by Rachel McKendry and Prof. Gabriel Aeppli, developed ultra-sensitive probes capable of providing new insight into how antibiotics work, paving the way for the development of more effective new drugs.

During the study, Dr McKendry, Joseph Ndieyira, Moyu Watari and coworkers used cantilever arrays to examine the process which ordinarily takes place in the body when vancomycin binds itself to the surface of the bacteria. They coated the cantilever array with mucopeptides from bacterial cell walls and found that as the antibiotic attaches itself, it generates a surface stress on the bacteria which can be detected by a tiny bending of the levers. The team suggests that this stress contributes to the disruption of the cell walls and the breakdown of the bacteria.

The interdisciplinary team went on to compare how vancomycin interacts with both non-resistant and resistant strains of bacteria. The ‘superbugs’ are resistant to antibiotics because of a simple mutation that deletes a single hydrogen bond from the structure of their cell walls. This small change makes it approximately 1000× harder for the antibiotic to attach itself to the bug, leaving it much less able to disrupt the cells’ structure, and therefore therapeutically ineffective.


A schematic representation to show the nanomechanical detection of antibiotic-peptide interactions on multiple cantilever arrays. The blue and white structures show chemical binding interaction between vancomycin and the bacterial mucopeptide analogue, DAla. The red line represents the mechanical connectivity of the chemically reacted regions on the cantilever.

“There has been an alarming growth in antibiotic-resistant hospital ‘superbugs’ such as MRSA and vancomycin-resistant Enterococci (VRE),” said McKendry. “This is a major global health problem and is driving the development of new technologies to investigate antibiotics and how they work.

“The cell wall of these bugs is weakened by the antibiotic, ultimately killing the bacteria,” she continued. “Our research on cantilever sensors suggests that the cell wall is disrupted by a combination of local antibiotic-mucopeptide binding and the spatial mechanical connectivity of these events. Investigating both these binding and mechanical influences on the cells’ structure could lead to the development of more powerful and effective antibiotics in future.”

“This work at the LCN demonstrates the effectiveness of silicon-based cantilevers for drug screening applications,” added Prof. Gabriel Aeppli, director of the LCN. “According to the Health Protection Agency, during 2007 there were around 7000 cases of MRSA and more than a thousand cases of VRE in England alone. In recent decades the introduction of new antibiotics has slowed to a trickle but without effective new drugs the number of these fatal infections will increase.”

The research was funded by the EPSRC (Speculative Engineering Programme), the IRC in Nanotechnology (Cambridge, UCL and Bristol), the Royal Society, and the BBSRC.

October 10, 2008: In a move to further extend its global distribution network, Nanosurf AG has appointed RL Artal Co. LLC in Budapest as its official agent for Hungary, and Anamet SRO in Prague and Modra, as its distributor for the Czech Republic and Slovakia. The cooperation with these local sales partners allows Nanosurf to tap into the emerging nanotechnology markets in Eastern Europe, and to better meet the need for easy-to-use and affordable atomic force microscopes (AFM) and scanning tunneling microscopes (STM) for education, research, and industry in this region.

Nanosurf’s main focus is on the research and development of scanning probe microscopes (SPM) and their accessories, with a particular emphasis on making them accessible to a broad user base by paying special attention to their ease of use, affordability, and reliability. Nanosurf’s engineering capabilities and technical know-how have led the Swiss company to be included in NASA’s Phoenix Mars mission with the first AFM to record images on another planet.


AFM scan of a carbon nanotube.

October 9, 2008: Holiday Creations/Diogen Lighting Inc. and Evident Technologies Inc. announced the signing of an exclusive licensing and purchase agreement to enable a new type of LED to be commercialized in the seasonal light strand market in the US and Canada. The technology is centered on semiconductor nanocrystals, also known as quantum dots, and allows for never-before-seen colors and new design possibilities for the fast growing LED decorative light strand market.

“As consumers become more aware of the energy savings afforded by LED lights, they are switching from the traditional incandescent lights. The problem with current LEDs is that their color selection is limited. Imagine if you only had five colors to choose from for painting, coloring or decorating,” stated John Hayes, CEO, Holiday Creations/Diogen Lighting. “This new technology gives us a wide range of colors for holiday and decorative lighting. We are excited to be able to offer these colorful new products to our customers immediately for sale in retail stores beginning in 2009.”

Traditional LEDs are energy efficient, but are fundamentally limited to a handful of colors like, red, blue, yellow and green. Phosphors can be used to alter the color but the color pallet is still limited. Evident’s quantum dot technology removes these limitations, and enables LEDs to emit any color, including high quality white light. Dotstrand Energy Efficient Lights are colorful strands utilizing these quantum dot LEDs and are distinctive for their attractive retail packaging design.

“We chose Holiday Creations as our partner for this technology because they are a progressive, forward-thinking, market leader with an established track record. We are eager to see their new line of light strand products and the Dotstrand brand in US and Canadian retail stores,” said Clint Ballinger, CEO Evident Technologies.

October 7, 2008: SUSS MicroTec, a supplier of solutions for the 3D, MEMS, advanced packaging and nanotechnology markets, announced that the capabilities of its manual mask aligners are now enhanced with a new nanoimprint toolkit that enables them to pattern large areas with repeatable sub-50nm printing capability.

The new technology, called substrate conformal imprint lithography (SCIL), has been developed by Philips Research, Eindhoven/The Netherlands and transferred to SUSS MicroTec in a technology license agreement.

SCIL is bridging the gap between small rigid stamp nano imprint lithography (NIL) application for best resolution and large-area soft stamp usage with usually limited printing resolution below 200nm. Its excellent performance in terms of substrate conformity and pattern fidelity over large areas makes this imprint technology a powerful tool, especially for applications such as high brightness LEDs, high-efficient laser diodes or BPM (bit patterned media) to use in next-generation hard disc drives.

The SCIL toolkit can be field-installed on any SUSS MA6/8 mask aligner.

a)

b)

a) SUSS MicroTec Logo printed in Amonil MMS 4 on a SUSS MA6 Mask Aligner. b) Section of U-letter with holes 160nm.