Qiming Zhang - US grants

ECS-9710459 Qiming Zhang The objectives of the proposal are: (a) To investigate structure/property relationships governing electromechanical properties or polymeric materials. (b) To provide understanding of electroprocessing/microstructure relationships in order to control design of electroactive polymers with optimized properties for end-use applications. (c) To develop new electroactive polymers with unique electromechanical properties leading to rapid technological development. (d) To shorten the time period between research concept, to increased scientific understanding, and new technologies and devices by close collaborative studies involving Rutgers University (Polymer Electroprocessing Laboratory) and Penn State (Materials Research Laboratory), combined with the chemical synthesis work of Allied Signal and end-use applications expertise of AMP, Inc.

ECS-9710278 Jerry Scheinbeim The objectives of the proposal are: (a) To investigate structure/property relationships governing electromechanical properties or polymeric materials. (b) To provide understanding of electroprocessing/microstructure relationships in order to control design of electroactive polymers with optimized properties for end-use applications. (c) To develop new electroactive polymers with unique electromechanical properties leading to rapid technological development. (d) To shorten the time period between research concept, to increased scientific understanding, and new technologies and devices by close collaborative studies involving Rutgers University (Polymer Electroprocessing Laboratory) and Penn State (Materials Research Laboratory), combined with the chemical synthesis work of Allied Signal and end-use applications expertise of AMP, Inc.

DESCRIPTION (provided by applicant): The objective of this EBRG program is to develop novel actuator technology for refreshable full-page Braille display and graphic display. Despite many years of R&D efforts to reduce the cost of the refreshable Braille display and to develop new technologies which can be used to produce practical full page Braille play and graphite Braille display, the Piezo Braille displays are still the dominating form for the refreshable Braille display. The bulky size, high cost, and fragility of the piezo-actuators make it impractical to use them for refreshable full-page Braille displays. In recent years, we have developed several novel electroactive polymers which generate strain two order of magnitude and elastic energy density one order of magnitude higher than these in the piezoceramics used in the commercial refreshable Braille displays. In this EBRG program, we will make use of this class of polymers to develop low cost, robust, compact actuators (order of magnitude reduction in size while maintaining same actuation capability) to replace the piezoceramic bimorphes, which will make the full-page Braille display and graphic display possible and practical. This EBRG program will combine the expertise at Penn State in the electroactive polymers and in actuator development with the expertise at View Plus on the Braille display. This combined expertise provides unique opportunity to develop these compact actuators to be directly transitioned to practical refreshable graphite Braille display and full page Braille display.

The research objective of this Nanoscale Interdisciplinary Research Team (NIRT) project is to develop and study novel hierarchical nanofilamentary materials and structures based on active continuous nanofibers. Ferro/piezoelectric materials represent a technologically important class of active materials and ferro/piezoelectric fibers and fiber-reinforced composites have distinct advantages for applications. However, current manufacturing techniques result in thick fibers with diameters in the tens to hundreds of microns leading to their poor processability and mechanical properties. In this project, hierarchical nanofilamentary materials and structures based on novel active continuous nanofibers will be nanomanufactured, studied, and developed. The project will build on the recent discovery of a nanomanufacturing technique capable of producing nearly perfectly aligned and dense bundles and yarns of continuous nanofilaments. Nanomanufacturing method will be further developed and optimized to produce hierarchical nanofilamentary structures from ferro/piezoelectric ceramic and polymer nanofibers. Mechanical and physical properties of these novel materials will be characterized and correlated to their multiscale architecture. Multiscale modeling and analyses will be performed and used to understand their behavior and to correlate it with their structure and processing parameters.

This research will have impact on nanomanufacturing, characterization, and modeling of active materials, nanofibers, and nanofiber assemblies and composites. This project will further advance our knowledge and understanding of nanofiber nanomanufacturing and behavior. Continuous nanofiber technology is attracting rapidly increasing interest in many fields and industries. The new materials and nanomanufacturing methods to be developed in this project will be used in a broad variety of applications. Educational component includes multidisciplinary research training of several PhD students and development of relevant new courses. Societal and ethical issues associated with nanomaterials research will be also explored in conjunction with the nanomanufacturing, characterization, and modeling research.

The co-existence of ferroelectricity and ferromagnetism in multiferroic materials opens up a host of new cross-coupled phenomena and enables entirely new device paradigms. This project seeks to develop self-assembled organic-inorganic hybrid nanostructures with coupled electric, magnetic, and structural order parameters at nanometer scale as a totally new form of multiferroic materials. Specifically, the ferromagnetic nanoparticles will be incorporated into the ferroelectric polymers via covalent bonding interactions for colossal magneto-electric effect. The block structures of ferroelectric polymers and ferromagnetic nanoparticles will be prepared and explored to the control of the nanoparticle aggregation via supramolecular self-assembly.
The success of this exploratory project will have profound implications for design and synthesis of active nanostructures with new architectures and multiple functionalities. Future scientists capable of working at the interface between traditional disciplines will be trained and educated within this program. Educational videos with supporting classroom materials will be produced for secondary schools, targeting the 7th through 12th grades.

[unreadable] DESCRIPTION (provided by applicant): The objective of this program is to develop novel electroactive polymer (EAP) actuator technology for refreshable full page Braille display and graphic display. Built upon the experiences and successful foundation laid by a R21 program, the goal of this work is to design and develop electroactive polymer Braille actuators with optimized performance, low cost, compact size, and high reliability and reproducibility. EAPs composition and processing conductions will be improved and optimized. Fabrication set-ups and processing procedures necessary for mass producing these Braille actuators with low fabrication cost will also be designed and developed. Braille cells will be designed and developed which can directly replace the piezoceramic actuator based Braille cell in the current single line refreshable Braille display and suitable for multiline and full page displays. The overall intent of this program is to expedite the creation of low cost, compact size, lightweight, and user friendly refreshable Braille displays, based on electroactive polymer actuators, that can directly replace the currently marketed cost-prohibitive Braille single line and can be easily implemented for multiline and full page Braille displays, thus allowing for the widespread access to those who would benefit from the use of such devices. A low cost multiline and full page refreshable Braille display system is needed so that the blind and visually impaired can more effectively access computer based information, enhancing their education and employment opportunities, and improving their quality of life. In recent years, we have developed several novel electroactive polymers which generate strain two orders of magnitude and elastic energy denisty one order of magnitute higher than these in the piezoceramics used in the commercial refreshable Braille displays. The results obtained by the R21 program show great promise that the EAP actuators under development can be successfully used for Braille actuators. This program will combine the expertise at Zhang's group in the electroactive polymers and in actuator development with the expertise at Rahn's group in mechatronic desigh that couples electrical and mechanical components in novel devices. The program at Penn State will be complemented by the expertises at ViewPlus on the Braille display. This combined experties provides unique opportunity to develop these compact Braille actuators with low cost, compact size, and optimized performance to be directly transitioned to practical refreshable graphite Braille display and full page Braille display. [unreadable] [unreadable] [unreadable]

Research Objectives and Approaches: The objective of this research is to develop ultra-sensitive and compact magnetometers, featuring the direct on-chip integration of magnetoelectric sensors, with advanced microelectronics, for non-invasive medical imaging. The approach is based on the potential of picoTesla magnetic sensitivity using integrated magnetoelectric composites. This research aims to further improve the sensitivity beyond those based on the direct stress mediated magnetoelectric coupling by improving the mechanical impedance match between the constituents, by exploring totally new magnetoelectric coupling, and by incorporating MEMs-based structures as resonant moving gates of MOSFETs for further amplification.

Intellectual Merit: The demonstration of a heterogeneous integration strategy at the devices and circuits level that seamlessly merges microelectronics with sensors holds great promise of enabling transformational shifts in the semiconductor and sensor industry. Further, the proposed research will provide fundamental understanding on the magnetic energy transfer efficiency between the constituents of the composites. The research will also provide insight into design and fabrication of resonant moving gate transistors that markedly improve the sensor performance.

Broader Impact: The successful development of chip scale magnetic sensors will revolutionize the field of biomagnetic field detection and imaging. Moreover, the availability of low cost diagnostic tools will greatly facilitate early disease detection. On the education and outreach font, this research will foster an interdisciplinary educational program that will inspire students to understand fundamental materials science and device physics and incorporate them into solid-state device fabrication to address complex detection and diagnosis problems in the life science and biomedical imaging area.

The research objective of this grant is to elucidate the fundamental micro- and nano-scopic processes that are responsible for the observed electromechanical responses in ionic electroactive polymers (i-EAPs). Electroactive polymers, because of their many attractive properties and characteristics including high strain response, low density, fracture tolerance, and pliability, are suitable for a broad range of sensing and actuating applications. i-EAPs that can be operated under a few volts are particularly attractive because this allows direct integration with advanced microelectronics, which opens up an entirely new device paradigm for multifunctional large-scale integrations. However, i-EAPs suffer relatively low efficiency as well as low actuation speed. The porous electrodes in traditional i-EAPs have a random morphology that physically impedes ion transport, resulting in slow response times and reduced efficiency. The proposed study will exploit i-EAPs with uniquely controlled and tunable nanostructure morphology and investigate ionic liquids that can maximize the strain generated and actuation speed. Ion size, and its transport through similarly sized (and controllable) nanoscale channels, has the potential to uncover new physics limiting transport. By systematically tailoring the nanostructure morphology, and varying the ionic liquids, we intend to unravel fundamental processes controlling the electromechanical response in the i-EAP materials and devices.

If successful, this interdisciplinary collaborative effort will expand the known i-EAP materials, allow the operation of i-EAP devices to much above the electrochemical window of the electrolytes, develop an understanding of ion transport and storage in nanocomposites with known nanostructure morphology, and provide structure-property relations for different ions in i-EAP materials. This collaborative program between Penn State and MIT will provide education and training of graduate students and undergraduate in a multi-disciplinary exchange context, ranging from nano-materials science and engineering, nanocomposites and MEMs fabrication techniques, advanced nano-materials characterizations, through to device-level integration. This program will pursue a proliferation of the broad-impact results from this program by disseminating video features depicting the broad energy applications of advanced materials and nanotechnology to high-schools and county libraries and other institutions and two graduate courses will be enhanced. The program will also actively disseminate knowledge through public media outlets as appropriate, such as institutional press releases and the Discovery & Science Channels.

Technical Description: The objective of this project is to synthesize and investigate iron oxysulfide, in particular sulfurized hematite, with the goal of replacing critical components in the current solar cell technologies for next-generation photovoltaics. Sulfurized hematite, with an appropriate concentration of sulfur, will potentially meet the cost and efficiency requirements for terawatt photovoltaics. The scientific tasks of the project include: 1) First-principles studies of iron oxysulfide and copper oxysulfide as solar photovoltaic materials; 2) Development of deposition and sulfurization methods for sulfurized hematite; 3) Investigation of its electrical and optical properties as a function of sulfur content; and 4) Development of solution-based n-type and p-type doping methods for hematite. The major innovations in this project include: 1) the use of three Earth-abundant elements, iron, oxygen and sulfur, for bandgap engineering to create a semiconductor better suited for solar photovoltaics; 2) the use of largely solution-based processes for film deposition and doping to ensure low-cost solar cells in the end; and 3) a multidisciplinary approach, where first-principles studies and experimental studies are joined to push forward the technology.

Non-technical Description: The success of this project will enable a sustainable solar cell technology, which is capable of low-cost, high-efficiency and most importantly terawatt-scale deployment, allowing solar electricity to become a major source of energy in our future. In addition, this project includes a targeted effort to increase the representation of American Indians in science and engineering as well as increase the awareness of local Arizona tribes on photovoltaic technologies. The principal investigators work with entities such as the American Indian Science and Engineering Society and Arizona Department of Commerce to promote photovoltaic technologies in remote tribal communities, provide research opportunities to American Indian science and engineering students, and engage and interest American Indian youth about science and engineering in general. This project also provides synergistic support to the newly-established U.S. Photovoltaic Manufacturing Consortium (PVMC) for its mission to facilitate a robust domestic solar cell industry. The success of this project will provide a technology pipeline for PVMC, while PVMC provides industrial connections for this project.

? DESCRIPTION (provided by applicant): Iron overload affects life of many people in the US and around world. Liver iron concentration provides a direct indication of body iron level. Among various noninvasive methods, Biomagnetic liver susceptometry (BLS) has been proven to provide the only direct means of determining hepatic iron stores. However, BLS requires cost- prohibitive (~ 1 million) and complex (~ 4 K, liquid helium) SQUID magnetometer, which limit the clinic adoption of this technology. The objective of this program is to develop a novel ultra-sensitive piezoelectric magnetic susceptometer for noninvasive liver iron assessment. Among various sensors, piezoelectric sensors offer many attractive features such as ultra-high sensitivity, low cost, and robust operation. However, very weak coupling of these materials to magnetic fields prevent them from been used for magnetic field sensing. Recent advances in the multiferroic materials, especially, the magnetoelectric (ME) composites, create unique opportunity for developing piezoelectric sensors for magnetic field sensing. This program will develop room- temperature-operated, low-cost, compact-size, robust, ultrasensitive magnetic sensors for BLS. In our preliminary study, we also developed a ME sensor with first-order gradiometer and characterized its sensitivity using human-liver size phantom with iron concentration from normal (0.05 mgFe/gliver) to severely overdose (5 mgFe/gliver) in an environment without any magnetic shielding. These results provide compiling evidence for feasibility of the ME-based BLS for liver iron quantification. In Aim 1, we will develop, characterize, and calibrate single element ME-based BLS. In Aim 2, we will develop an array ME-based BLS taking advantage of its compact size. Array BLS will enable characterization of liver iron concentration distribution which would allow for reduction of confounds of comorbid pathologies (e.g. cirrhosis and fibrosis). The BLS technology to be developed in this program is both conventional and disruptive. It is conventional because this technology will adopt the principle of SQUID-base BLS which has been proven to be effective in quantifying LIC. It is disruptive because the technology can lead to breakthroughs in cost and size, which would ultimately allow us to develop a portable Doctor's office or patient bed-side BLS device in the future RO1 applications.