New materials for any job

FAPESP Week California spotlights technologies for particle control and glass-ceramic compounds, both having applications in a variety of fields from medicine to consumer electronics

By Heitor Shimizu, in Berkeley

Agência FAPESP – When American artist Jackson Pollock (1912-1956) popularized the technique of painting by dripping or hurling paint onto canvases, little could he imagine that decades later his art principle would become the focus of research in several laboratories and have important industrial applications in a variety of fields.

Understanding the behavior of particulate systems – paint droplets are one example – and controlling their dynamic are objectives of the center directed by Tarek Zohdi, full professor of Mechanical Engineering and chair of the Computational Science and Engineering Program at the University of California, Berkeley (UCB).

In a lecture given November 18, 2014, during FAPESP Week California at UCB, Zohdi talked about the challenges of research on particulate systems in the presence of strong electromagnetic fields.

The research involves several fields, from engineering, microelectronics, biology and mathematics. There are countless applications, from flux control of particles on an electronic screen, to the development of inkjet application processes (such as that found in printers or electrostatic paint machines), to applications of particles inside cells in drug therapies.

“My research group at UCB is investigating modeling and simulation of manufacturing processes on particulate materials. An example of this are sprays, currently big in Silicon Valley, on which we are researching the application of tiny particles on a surface, which can be done with enough pressure to cut these surfaces or at least form layers of material on the surface,” Zohdi said.

One application of this technology that is starting to become popular is in 3D printers that operate from depositing synthetic material particles on top of each other to form volumes.

Zohdi explains that in manufacturing processes, particles can be applied by deposition, by impression or by spraying. The manner, that is, the technology of how the application is done, influences the result of the process and involves several factors. Spray-painting an automobile for example involves different challenges than painting a boat, which is in constant contact with water, subjecting the paint particles to different forces.

Zohdi, organizer of FAPESP Week at UCB, has been working with Brazilian researchers for more than 10 years. The research exchange with Prof. Paulo de Mattos Pimenta, in the Department of Structural and Geotechnical Engineering at the Polytechnic School of the University of São Paulo (USP), led UCB and USP to sign an academic cooperation agreement in engineering in 2013. The agreement enables the exchange of undergraduate, graduate and post-graduate students, post-doctoral researchers and professors.

Glass-ceramic materials

In his lecture during FAPESP Week California, Edgar Dutra Zanotto, full professor at the Federal University of São Carlos (UFSCar) talked about the Center for Research, Teaching and Innovation in Glass (CEPIV), which he runs.

Based at UFSCar, the CEPIV – one of FAPESP’s Research, Innovation and Dissemination Centers (RIDCs) – was established in 2013 and brings together 14 researchers and close to 50 students from UFSCar, the University of São Paulo (USP), São Paulo State University (Unesp) and from other institutions, along with experts in the fields of engineering, chemistry and physics of glass materials.

CEPIV’s principal objective is creating glass-ceramic materials with new functionalities. The researchers are investigating such things as developing new optical materials, materials for structural reinforcement in dentistry, and devices for storing energy.

“CEPIV is one of the largest academic groups in the world doing research on glass materials. Our proposal is to do basic research using structures and relationships between molecular structures, which involves areas such as structural design and crystallization, dynamics, functional characterization and optimization and their relationships to properties, be they mechanical, biological, electrical, optical or chemical,” Zanotto said.

“From the technology standpoint, we are investigating materials for such things as construction, dental materials, batteries, lasers and catalytic converters,” he said.

Zanotto explained that glass ceramics exist in nature. “They are glasses that partially crystallize, that contain crystals that somehow develop inside glasses,” he said.

In 1953, Stanley Stookey, then a young researcher at Corning Glass, in the U.S., discovered how to artificially produce the type of materials that are used today in dental implants, kitchen cook-tops and telescopes.

“Glass-ceramic materials are very important because they allow us to combine properties. For example, we can make a bioactive material that is much harder and resistant than glass, or we can make a transparent glass-ceramic with very high thermal conductivity, or high electrical conductivity and chemical stability,” Zanotto said.

“There are lots of research opportunities to explore in glass-ceramic materials, from the standpoint of basic research as well as application of the technology. The future is bright in this field and we are just getting started,” said Zanotto, who coordinated the FAPESP-funded thematic project, “Kinetic processes in glasses and glass ceramics“.

FAPESP Week California continues at the University of California, Davis November 20-21, 2014. The symposium is supported by the Brazil Institute of the Woodrow Wilson International Center for Scholars, in Washington, DC.