Dr. Chris Weinberger’s Advancements to Shape Memory Industry Published by Nature Communications

This past fall, ME Professor Chris Weinberger’s groundbreaking research in shape memory materials was published by the prestigious journal, Nature Communications.

The article, entitled, “Superelasticity and Cryogenic Linear Shape Memory Effects of CaFe2As2,” was recognized for its discovery of an innovative shape memory material which has the potential to advance deep space exploration, and eventually revolutionize the shape memory industry.

Conventional shape memory alloys are solid state actuators and are used in a wide range of industrial applications replacing traditional methods of actuation including hydraulics, pneumatics, and other motor-based actuators; however, there are a number of practical issues associated with shape memory alloys that include dimensional instability, fatigue, and limitations to functionality under extreme temperatures. With this knowledge, it was desirable to identify alternative shape memory materials.

A group of 12 researchers, including Dr. Weinberger, demonstrated that a new class of materials are capable of both shape memory properties as well as superelasticity. CaFe2As2, a material similar to conventional shape memory alloys but less susceptible to dimensional instabilities and fatigue, showed promising results. The material was also known to be a superconductor that could undergo a temperature dependent phase transition. When CaFe2As2 was put to the test and cycled through 100 actuations with no changes in properties, the group was optimistic.

Final results concluded that CaFe2As2 exhibited unparalleled results when compared with any currently known shape memory material.  In addition, the operation temperature of the shape memory effect is extremely low, between 50 and 100K, suggesting that this type of shape memory material could be developed for space applications.

Perhaps more importantly, the discovery of superelastic and shape memory properties of CaFe2As2 has the potential for advancing several industries, not just deep space exploration. CaFe2As2 properties can be tuned, allowing for customization of the chemical composition of the material which would allow engineers to tailor the actuation temperatures and the actuation work. Furthermore, since there are over 400 known compounds that are similar to CaFe2As2, this research has demonstrated that this discovery only scratches the surface.

Dr. Kurt Barth Investigates Advancements in Thin Film Photovoltaic Devices

Kurt Barth, associate director of CSU’s Next Generation Photovoltaic Center, received $1.3 million (the Colorado Renewable Energy Collaboratory is contributing significant cost share) for a project titled “Advanced Module Architecture for Reduced Costs, High Durability and Significantly Improved Manufacturability.”

Barth’s project will investigate new materials and methods for enhanced durability and reliability of thin-film photovoltaic devices. One of the goals is refining a new manufacturing process for solar modules that’s faster and cheaper than conventional techniques. “We are very excited about this project and the opportunities to improve solar module manufacturing,” said Dr Barth. For the project, the CSU center is partnering with the National Renewable Energy Laboratory and the PV Manufacturing Corp. at the State University of New York.

Contributions made by Anne Manning.

The Center for Next Generation Photovoltaics Continues to Advance Solar Energy

Drs. Walajabad Sampath and Amit Munshi investigate solar energy advances with PVRD grant.

The U.S. Department of Energy under the Photovoltaics Research and Development (PVRD) program, recently awarded Dr. Walajabad Sampath with the Small Innovative Project in Solar (SIPS) Award, to investigate improved solar energy efficiency without substantially increasing manufacturing costs. Implementing CdTe (Cadmium Telluride) solar electricity as a major source of energy throughout the world would not only give third-world nations access to affordable electricity, but address climate change by reducing greenhouse gases in our atmosphere.

Since 1991, Dr. Sampath’s research group at the Center for Next Generation Photovoltaics, has been at the forefront of CdTe thin-film solar cell research. In the last few years, achieving higher solar cell efficiency without increasing the cost of manufacturing has become a growing challenge in the field.

PI Dr. W.S. Sampath (left) and Co-PI Dr. Amit H. Munshi (right) holding the record 19.1% efficient CdTe solar cell.

Currently, the lowest cost of electricity recorded using CdTe solar panel technology without government subsidy is ¢3.8/kWh. This is substantially lower than the average cost of electricity in U.S. which is about ¢11/kWh.

Principle investigator Dr. Sampath, and co-principal investigator, Dr. Amit Munshi have identified the specific challenges involved, and are optimistic about bringing their research to fruition. First, they plan to investigate the use of a lower bandgap material which would allow more light to be absorbed in the solar cell leading to higher efficiency. Some initial work has been done using this method where the CdTe layer was graded with selenium (Se). This formed a CdSeTe layer where the light first hits the solar cell, then gradually turns into CdTe. Initial results using this method have led to the demonstration of 19.1% efficient CdTe solar cell. This is the highest solar cell efficiency demonstrated using CdTe by any university or national laboratory in the world, and demonstrated even higher at 22.1% by First Solar Inc.

The second major challenge that Drs. Sampath and Munshi will focus on is the limitation in voltage of these solar cells due to the inefficient doping of CdTe. This is a fundamental challenge identified by researchers globally. At an attempt to remedy the issue, a metal organic chemical vapor deposition gas with a group V dopant will be injected during deposition of CdTe films. If successful, this will be the first-ever polycrystalline CdTe solar cell of its kind to produce 1 V with only 3-5 micrometers of material.

“We truly enjoy our work in this exciting and fast-paced field and look forward to paving the way for a new breed of highly-efficient, affordable, and sustainable solar technology to advance the industry further,” said Dr. Munshi.

The Center for Next Generation Photovoltaics is a National Science Foundation-supported Industry/University Cooperative Research Center at CSU. Commercial members include leaders from the energy sector and across the solar technology chain.

Contributions made by Anne Manning.

The Factory

Since the 1950s, a 24,000-square-foot, off-campus research facility, located in the Fort Collins foothills, has endured dozens of renovations; the latest renovation transformed the facility into “The Factory.” Its diverse history has made it one of CSU’s most unique facilities, and its new name offers a glimpse into its inception in 1958.

The most recent renovations were initiated to provide research spaces for two new faculty members, Drs. Kaka Ma and Chris Weinberger, and as part of the development for the University’s newest interdisciplinary program, The School of Advanced Materials Discovery.

An image of the Factory today.

From 2002-2017, the facility was known as the Motorsport Engineering Research Center, or “The MERC,” to the CSU community. The center’s initial goal was to accommodate faculty and students involved in motorsport-related research, design, and development; however, with the economic downturn, the demand for motorsport engineering diminished, so the department diversified the facility in 2014.

Since 2004, the facility has also been home to the Composite Materials, Manufacture, and Structures research lab run by Dr. Donald Radford, and, more recently, the Advanced Materials Processing and Testing Lab, both of which continue to operate today. For many years, the Formula SAE Ram Racing team used the MERC to develop their racecars. Past FSAE president, and now ME alumnus and advisory board member, Adam Grabish, ’15, remembers his experiences there.

“The MERC was my home away from home for three years. FSAE was as much as part of the MERC as the MERC was a part of FSAE. I am the engineer I am today because of my time spent on the team, and I wouldn’t trade my experiences for anything.” When Dr. Thomas Bradley joined the department in the fall of 2008, the EcoCAR program also operated at the MERC for a short time, along with other senior design activity from 2004-2014.

Dr. Kaka Ma’s new lab space.

The center also housed an assortment of state-of-the-art computational and advanced manufacturing equipment, and a wireless network that covered the majority of the 10- acre site – optimizing data transfer from racecars to laboratories. In addition to research, the adjoining MERC Annex included a conference and education center allowing for courses and training to take place.

In the 1960s, the 14,000-square-foot site was acquired by CSU, and, until 2002, was used for agricultural engineering research. Extensive renovations that took place during this time included the development of the annex, the building of a Food Extrusion Laboratory, the addition of meeting rooms and offices, the building of a machine shop, and, finally, the introduction of an indoor crop research lab. The AERC moved to the Agricultural Research, Development, and Education Center in 2002.

In 1958, the Silvaire Aircraft Factory built this facility to assemble 80 Luscombe Silvaire aircraft. At the time, this area of Fort Collins was envisioned as a technology park by J.D. Forney, a local businessman, who persuaded the Silvaire Company to locate in Fort Collins. This site was appealing for aircraft development due to its proximity to Christman Field, which allowed completed aircraft to be moved directly to the airport.

The Factory is an ever-changing piece of Fort Collins’ history that has made an impact at each stage of its existence. Its longevity has given it character and importance in the community, and we look forward to what the future holds for this research facility that has provided academic enrichment to engineering students for decades. If you are interested in touring this new space, contact Sona Srinarayana – sonas@colostate.edu – for more information.

National Science Foundation Next Generation Photovoltaics Center at CSU

Dr. W.S. Sampath, site director of the National Science Foundation Next Generation Photovoltaics Center at Colorado State University, has been working on advancing cadmium telluride (CdTe) Photovoltaics for more than 20 years at CSU. Along with Dr. Kurt Barth, the associate site director of the NGPV Center, the overall vision is to help establish PV electricity as a major source of energy in the United States and the world by leveraging cutting-edge research.

Many of of NGPV Center's CdTe research contributions led to First Solar's 290-megawatt power plant with CdTe PV (7.5 sq. mi.)

Many of of NGPV Center’s CdTe research contributions led to First Solar’s 290-megawatt power plant with CdTe PV (7.5 sq. mi.)

The demand for advanced PV technology is at an all-time high. The PV industry has consistently seen 40 percent growth each year for more than a decade, and it’s also becoming increasingly competitive with traditional electricity generation due to technology advances. Bloomberg recently reported that CdTe PV produces the lowest-priced electricity in the nation today; the prices have decreased 75 percent in the last four years and the trend is predicted to continue.

The NGPV Center is unique in PV research for a variety of reasons:

  • It’s a National Science Foundation Industry/University Cooperative Research Center
  • The NGPV Center uses CdTe as a semiconductor as opposed to silicon-based semiconductors to extract solar energy. CdTe uses 100 times less semiconductor material that can be 100 times less pure than silicon. CdTe is less expensive to manufacture, readily available, safe, 100 percent recyclable, better performing, and is in general, a more effective material for this purpose.
  • The NGPV Center has helped to streamline the manufacturing process of solar panels. These advances have directly enabled CdTe PV to become the leading PV technology in the U.S.

The NGPV Center invites the industry to join its mission by becoming members. Contact Dr. W.S. Sampath if interested, sampath@engr.colostate.edu. With member support, the NGPV Center can build a more robust program and offer its members exclusive benefits such as providing direction for new research, encouraging close interactions with other PV industry leaders, awareness of new technologies and opportunities, IP arrangements, and more.

With a handful of partners, including First Solar, 5N Plus, the National Renewable Energy Laboratory, Loughborough University, Ion Edge Corp., and MBI Corp., the NGPV Center is well on its way to making PV electricity a major source of energy.

The New School of Advanced Materials Discovery

Colorado State University’s dynamic and extensive materials and manufacturing research is only magnified by today’s heightened interest in advanced materials solutions that significantly impact basic human needs such as energy, transportation, health, food distribution, and more. Engaging students in this expanding field through a new and exciting program is the shared vision of chemistry professor and director of CSU’s new School of Advanced Materials Discovery, Dr. Ellen Fisher, and a steering committee that includes mechanical engineering Department Head Sue James, and materials-focused, mechanical engineering Assistant Professor Troy Holland. The SAMD is on schedule to complete the final approval hurdles in the upcoming academic year and plans to admit only graduate students in fall 2016. The planned offerings include M.E., M.S., and Ph.D. programs in materials science and engineering.

The demand for this new program couldn’t have come at a better time. CSU has a strong cohort of faculty conducting materials and manufacturing research; at least 60 CSU faculty members have identified interests in materials research and education. In a recent faculty survey, nearly all expressed strong interest in the SAMD and in mentoring the SAMD students. Students were also surveyed, and a majority of undergraduates noted that they would consider this multidisciplinary graduate program, and the lion’s share of graduate students noted they “definitely” or “probably” would’ve been interested in the program when they applied to CSU. Industry partners have also shown interest in hiring CSU M.S.E. graduates. A majority of partners surveyed anticipate M.S.E. positions being available in the next five years.

There are currently 90 doctoral materials programs in the country, two of which reside in Colorado – the Colorado School of Mines, and the University of Colorado Boulder. Even so, the Great Plains and Rocky Mountain regions don’t offer a program with the SAMD’s focus. Distinct program elements include training in materials computational tools, additional hands-on training with materials instrumentation, specific instruction in materials intellectual property and technology transfer innovation, and professional development. The program will also offer students a composites manufacturing lab and the benefits of industry partnerships and internships. The program will focus on 11 research areas, including areas of current strength for CSU’s materials community such as soft materials, materials for energy and sustainability, nanomaterials, biomaterials, and composites.

Notably, materials and manufacturing research within the mechanical engineering department is advancing at a rapid pace. Dr. W.S. Sampath is making huge strides in the field of photovoltaics at one of CSU’s research facilities; Dr. Don Radford was recently selected for a National Network for Manufacturing Innovation grant for his research in fiber-reinforced wind turbines; and Dr. Troy Holland recently ramped up his research by initiating his own lab, the Advanced Materials Processing and Testing Lab. The advent of the SAMD initiative will undoubtedly further advance these efforts and raise the visibility of our materials researchers’ innovations.