Current classes include:
MTX 105: Contemporary topics in materials (Materials and Medicine for the Year 2020)
This general education course is mainly concerned with current and future medical implants: their design and manufacturing, ethical and legal issues, their interaction with the body, safety, cost and effectiveness. A goal of this course is to develop the skills necessary to make a quantitative judgement on the value of a treatment, the plausibility of an argument or the reliability of a design. This year (2010) the course will be taught in a blended online and in person format. (more)
MTX 255: Biology for Engineers
Biology is increasingly a component of engineering. Chemical engineering R&D first morphed substantially into Bio-chemical engineering. Mechanical engineering research is developing a strong biomechanics flavor and a major part of Materials engineering in now on biomedical materials. The other engineering disciplines will follow soon. As a result biology should be a required area of knowledge for engineers alongside chemistry and physics, but there is little agreement on what parts of biology are wanted. The premise for this course is that the biology topics should parallel equivalent engineering topics. Thus it covers design and evolution, biomechanics, synthetic and natural composite materials, nerve signal transmission, ecology and sustainability, synapses and data storage. This course is in its third cycle in 2010, it will run as a blended course drawing heavily on wikipedia for readings. (more)
MTX 460: Materials and Design
Ashby has persuaded engineers that materials selection can be as much a logical component of design as can structural form, heat or current flow. This course follows the sequence set out in Materials: Engineering Science, Processing & Design by Michael Ashby, Hugh Shercliff and David Cebon although the content is substantially modified away from metals to soft materials. Throughout the course the discussion is supplemented by Quickfield, a free finite element program that is simple enough to allow focus on the materials selection rather than the details of shape and loading. (more)
Other courses taught recently
MTX 210: Properties of Materials (more)
MTX 410/510: Polymer Chemistry (more)
MTX422/522: Advanced Electronic Properties(more)
Current ResearchThe current research of the group revolves around approaches to making soft strong devices for biomedical or commercial applications. The chief tools in the laboratory are inkjet printing and freeform fabrication for sample preparation; diffusion, swelling and mechanical properties for characterization and finite element modeling.
Recent & Current projects include:
The properties of photovoltaic fibers woven into fabrics are being tested by Anshul Agrawal in collaboration with Konarka Corp. We are weaving their fibers into textiles and testing the PV characteristics for different fabric designs.(more)
Transparent, flexible textile electrodes funded by the National Textile Center and done by Bin Hu. PEDOT printed onto textile can give a combination of transparency and conductivity that rivals ITO on glass but is combine with flexibility. The efficency of this electrode is demonstrated for flexible printed electroluminescent lamps.(more)
Present sensors tend to be monlithic units that ideally have a linear reproducible response to a single stimulus. In contrast biologic sensors tend to have none of these charactersitics but work well because inputs from many sensors are sampled simultaneously. We are working towards arrays of printed sensors that could also be analyzed in parallel.(more)
Conducting ionic hydrogel sensors are being attached to knitted fabric sleeves in order to monitor the motion of the wearer. Impedance testing is used to detect strains in the fabric which can be correlated with the motion of an elbow or knee joint. These gel sensors are less sensitive than our conducting polymer or carbon-gel composite sensors but do not have the rapid transients or hysteresis of the other sensors. A key component is the development of reliable but flexible connections to the connecting leads woven into the fabric. The work is being done by Prakash Manandhar and is supported by the National Textile Center.(more)
Earlier work on printed PEDOT conducting polymer sensors supported by the National Textile Center is being followed up by Sagar Patel to find a strain sensor that will work to high strains over 20% on knitted Lycra fabrics that would be most likely to be used in a wearable sensing system. Epoxy hydrogels filled with conducting carbon black will give a reliable response to strain of 30%.(more)
Inkjet printed copper and nickelAny printed sensing system will also need printed conductors. With support from ICI Plc and its successor Henkel Plc, metal lines have been inkjet printed by Dapeng Li using a two-color printer to deposit metal salt and reducing agent simultaneously so that the metal forms on the porous paper or textile substrate.(more)
Printed chemical sensors based on carbon-filled hydrogels were studied by Deepak Duggal. Glucose oxidase bound into the gel causes a pH change and change in gel volume in the presence of glucose and this leads to a resistance change. (more)
Phage sensors. With support from the Army Research Labs., Dapeng Li has attached phage particles to hard and gel surfaces in order to test them as sensors for pathogenic bacteria.(more)
Laser-cured adhesive stitching has been studied by Amrut Sadachar with funding from the National Textile Center. New small blue solid state lasers provide enough power to rapidly cure small dots of acrylates deposited using a robot on textiles to stitch layers together.(more)
Printed antennae have been developed by Arpit Laddha with funding from the National Textile Center. Inkjet printing is used to deposit conducting polymer and silver onto a textiles to make a flexible patch antenna for 2.4GHz. (more)
Cartilage is a soft, strong gel whereas most synthetic gels are relatively weak and tear easily when cut. If we had strong gels they would be used for soft medical implants where the ability to control surface properties and the transparency to diffusing molecules could lead to far more biomimetic implants. Strong gels could also be used for engineering soft, wet machines to complement our current rigid, impermeable mechanical design. (more).
Fiber reinforced gels are being made by Animesh Agrawal with funding from the National Textile Center. Our freeform fabrication system builds a 3-dimensional mesh of 50 micron rubber fibers that is then impregnated with hydrogel to form a soft composite. The toughness of these fiber-reinforced gels is being studied and modeled.(more) MRS paper
3D gel mesh bioreactors are being built by Swati Mishra using the freeforming system to photopolymerize acrylate hydrogels. Yeast or animal cells are incorporated into the strands of the mesh, thereby immobilizing the cells but allowing them to metabolize and release metabolites into fluid flowing through the mesh.(more)
Inkjet printed hydrogels for tissue engineering are being developed by Skander Limem with support from the Tufts Tissue Engineering Research Center. Silk and collagen can be printed but tend to block nozzles. A two-color inkjet printer is being used to print anionic and cationic polyelectrolytes, such as polylysine and polyglutamic acid. They combine on the substrate to form an insouble cytocompatible hydrogel. (more)
Bionic gel devices are the focus of a collaboration with the University of Wollongong. The polyelectrolyte gels are being printed over soft electrodes in order to build electrically-controllable protein release systems. (more)
Stabilization of natural dyes
In collaboration with Prof. Charlene Mello and with Rutgers and Brown, we are studying the photo-oxidation of natural dyes encapsulated in nanoparticles with high levels of antioxidants. We find much enhanced stability which we currently attribute to dye-stabilizer complex formation. This may explain the high levels of antioxidants found in many fruits and vegetables. This work is supported by the NSF.(more)
Starting from a PhD on polymer crystallization, my research has progressed through additive distribution in crystalline polymers, dental composites, crystallization of proteins and biomolecules to biomimetic composites and ceramics based on in situ formation of the reinforcing particles. This in turn led to biomimetic layerwise processing by extrusion freeform fabrication and then by inkjet printing. The current long term aim is to inkjet print a rat.
Writing and Editing
From about 1975-1990 I wrote regular articles for the News and Views section of Nature, highlighting current materials research that seemed to have implications beyond its immediate topic. For a dozen years I was one editor of Materials Science and Engineering C: Biomimetic Materials. Currently I am editing/assembling a book for Wiley on carbon nanotube composites in addition to catching up on a backlog of papers and writing a couple of reviews.
I was chair of the Textile Science Department at UMassD from 2003-2006 and helped the conversion to a Materials and Textiles Department. This change has considerable logic as textiles are our best example of soft materials and the mephasis of materials research has very much shifted to soft materials. Since then I have been co-director of the Biomedical Engineering interdepartmental PhD program and spent one year as Associate Dean for Research and Graduate Education.