Dr. Tushar K. Ghosh
Textile Engineering, Chemistry, and Science
Examples of Recently Completed and Current Research Projects:
Functionally Tailored Textiles: 3-D Structures Through Melt Blown Technology: The research is aimed at developing appropriate technology necessary to produce three-dimensional molded garments to produce low cost combat uniforms with effective barrier characteristics, using minimal joining. The system being developed is called Robotic Fiber Assembly and Control (RFAC) system. RFAC system will allow incorporation of fibers, powders, or other appropriate additives into the garment systems. The additives may identify, measure, absorb, and/or deactivate chemical/biological agents. In the RFAC system deposition of meltblown fibers on an appropriate mold is controlled by a six axis industrial robot. The system allows precise control of fiber orientation distribution, fiber diameter distributions and pore size distribution.
Woven Fabric-based Electrical Circuits (Electro-textiles): Fabric-based electrical circuits are fundamental to electrotextile products of the future. The objective of the current research is to develop fabric-based electrical circuits by interlacing conducting and non-conducting threads into woven textile structures for civilian as well as military applications. Wired interconnections between different devices attached to the conducting elements of these circuits are made by weaving conductive threads so that they follow desired electrical circuit designs. In a woven electrically conductive network, routing of electrical signals is achieved by the formation of effective electrical interconnects and disconnects. Resistance welding is identified as one of the most effective means of producing crossover point interconnects and disconnects. These circuits are evaluated for signal integrity issues (crosstalk, etc.). Two new thread structures - coaxial and twisted Pair copper threads to minimize cross talk have been developed and evaluated. Significant reductions in crosstalk were obtained with the coaxial and twisted pair thread structures when compared with bare copper thread or insulated conductive threads.
Development of Fiber Actuators: Fiber actuators are capable of dimensional change under applied electrical field. Dielectric elastomer based prototype fiber actuators have been developed using commercially available dielectric elastomer tubes and by applying appropriate compliant electrodes to inner cavity and outer walls of these tubes. The force and displacement generated by such actuators have been studied under different isometric conditions and as a function of applied electric field. The actuation characteristics such as, axial strains, radial strains, and actuation blocking forces produced in the prototype upon actuation were studied. Actuation strain and blocking force are strongly influenced by the applied prestrain and have a parabolic relationship to applied electric field. High actuation strains (>50%) are currently afforded by dielectric elastomers at relatively high electric fields (>50 V/µm). A new class of electroactive polymers, suitable for fiber formation, have been developed by incorporating low-volatility, aliphatic-rich solvent into a nanostructured triblock copolymer yielding physically crosslinked micellar networks that exhibit excellent displacement under an external electric field. Ultrahigh areal actuation strains (>200%) at significantly reduced electric fields (<40 V/µm) has been achieved.
Electroactive Nanostructured Polymers as Tunable Actuators: Lightweight and conformable electroactive actuators stimulated by acceptably low electric fields are required for emergent technologies such as microrobotics, flat-panel speakers, micro air vehicles and responsive prosthetics.1,2 High actuation strains (>50%) are currently afforded by dielectric elastomers at relatively high electric fields (>50 V/µm). In this work, we have developed a nanostructured copolymer blend that yields a physically cross-linked micellar networks and exhibit excellent displacement under an external electric field. Such property development reflects reductions in matrix viscosity and nanostructural order, accompanied by enhanced response of highly polarizable groups to the applied electric field. These synergistic property changes result in ultrahigh areal actuation strains (>200%) at significantly reduced electric fields (<40 V/µm). Use of nanostructured polymers whose properties can be broadly tailored by varying copolymer characteristics or blend composition represents an innovative and tunable avenue to reduced-field actuation for advanced engineering, biomimetic and biomedical applications.
Design, Characterization and Processing of Carbon Nanofiber-Modified PVC as Fabric Sensor Composites for E-Textiles:The research aims to use screen-printing to fabricate an elastic and conductive nanocomposite layer of Plastisol, plasticized poly(vinyl chloride) (PVC), and carbon nanofiber (CNF) on textile fabrics to produce a piezoresistive strain-sensing substrate. The fabric sensor composite (FSC) being developed is based on the hypothesis that an elastomeric layer containing conducting nanoparticles printed on fabric substrates can yield a flexible, piezoresistive coating that can be tailored for specific applications. The research marries the demonstrated utility of plastisol as a print medium with the novelty of CNF-based polymer nanocomposites as applied to FSCs designed for use in electronic textiles. Previous studies have repeatedly identified benefits of CNFs relative to their CNT analogs, but relatively few studies have focused on conformable nanocomposites containing CNFs. The work seeks to establish a fundamental understanding of the physical factors governing CNF dispersion, percolation and subsequent mobility (upon drying) in a solvated polymer system (plastisol print medium) as a necessary prerequisite to the rational development of the target FSC. Insight into the percolation behavior of CNFs embedded in plastisol and subsequent property evolution will help to elucidate and further optimize the piezoresistive behavior of the FSC. Thus far, the percolation threshold of the plastisol-CNF was observed to be at ~2wt% and that the concentration of CNF where the resistivity starts to saturate is observed to be at 5wt%. Another significant observation is the increase of about 8 orders of magnitude in the conductivity of the composite when the concentration of the CNF was increased from 2wt % to 5wt %.
Most Recent Publications
1. Subramani, K. B., Cakmak, E., Spontak, R. J., Ghosh, T. K., (2014). "Enhanced Electroactive Response of Unidirectional Elastomeric Composites with High-Dielectric-Constant Fibers,?. Adv. Mater., , 26 , 2949.
2. Toprakci, H. A. K., Kalanadhabhatla, S. K., Spontak, R. J., Ghosh, T. K. (2013). "Polymer Nanocomposites Containing Carbon Nanofibers as Soft Printable Sensors Exhibiting Strain-Reversible Piezoresistivity,". Adv. Funct. Mater. , 23 , 5536.
3. Vargantwar, P. H., Ozcam, A. E., Ghosh, T. K., Spontak, R. J. (2012). "Prestrain-Free Dielectric Elastomers Based on Acrylic Thermoplastic Elastomer Gels: A Morphological and (Electro)Mechanical Property Study". Adv. Funct. Mater. , 22 (10) , 2100-2113.
4. Chakraborti, P., Toprakci, H. A. K., Yang, P., Di Spigna, N., Franzon, P., Ghosh, T. (2012). "A compact dielectric elastomer tubular actuator for refreshable braille displays". Sensors and Actuators: A Physical , 179 , 151-157.
5. Ghosh, T. K., Eadie, L. (2012). Biomimicry in Textiles: Past, Present and Potential, Presented at the 4th International Conference on Smart Materials, Structures, and Systems. CIMTEC 2012 . Publisher: Montecatini Terme, Tuscany, Italy.
Tushar K. Ghosh, Professor, College of Textiles, North Carolina State University, holds a doctorate degree in Fiber and Polymer Science. He joined the faculty at NCSU in 1987, and has since been a visiting Professor at the University of Sydney and the Indian Institute of Technology at Bombay. He has been named Outstanding Teacher of the Year and selected for the Circle of Excellence by the National Textile Center. In 2007, he was the recipient of the Fiber Society?s Founder?s Award for outstanding contributions to the science and technology of fibrous materials. His research activities are devoted to the mechanics of fiber assemblies, characterization of fibrous materials, design and development of functional fibers, and fiber-based structures for adaptive and responsive textiles. His current interests include the fabrication of sensors and actuators involving polymer nanocomposites, electroactive polymers, artificial muscle and biomimetic systems.
Professor Ghosh has been teaching various technology courses at both graduate and undergraduate levels. In recent years he has taught courses on weaving technology, functional textiles, and characterization of textile materials. Dr. Ghosh has served as consultant to many public institutions and industries on issues related to textile technologies and performance of textile products. He has published and presented more than one hundred scientific and technical papers in peer reviewed journals and conferences.
TT 351: Woven Fabric Technology
Design and development of various woven textile products including their component properties, performance requirements, structures, and methods of production. The primary objective of the course is to introduce students to various woven textile products, including those used in automotives, agriculture, construction, etc. and stimulate understanding of their structure, performance requirements, and relevant manufacturing principles including braiding.
TT 331: Performance Evaluation of Textile Materials
Standards, principles and effects of test conditions in measuring basic physical and mechanical properties of textile materials are discussed. Also covered are design of test and interpretation of test results in relation to end-use performance, product development, process control, research and development and other requirements.
TT 581: Technical Textiles
The course covers broad areas of industrial textile products in terms of their component properties, design, performance requirements, and methods of manufacture. The primary objective of the course is to introduce students to various industrial textile products, and stimulate understanding of their end-use driven design and manufacturing principles. Products covered are, Geotextiles, Tire-cord, Seat belt, Air-bag, Sail cloth, Parachute fabric, Reinforced rubber goods, Paper machine fabrics, Architectural textiles
Ph.D. , Fiber and Polymer Science , 1987
North Carolina State University
M.S. , Textile Materials and Management , 1984
North Carolina State University
M.Tech. , Textile Engineering , 1978
Indian Institute of Technology, New Delhi, India
B.Sc. Tech., Textile Technology , 1975
University of Calcutta , India