Materials development for sensing and biosensing

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 Many biosensors address medical needs, and are employed in diagnostics applications. The application of chemical sensors and biosensors for environmental and agricultural sampling, and for the detection of select biological agents associated with bio-terrorism is also rapidly increasing. We have developed a large array of materials to serve as substrates for detection devices. Grpahene oxide is one of the materials that have been most promising due to its large surface area and capacity for easy chemical functionalization. Current interests include the design of lateral flow devices for the detection of E. Coli O157:H7 in food, materials for assesment of meat freshness, as well as materials for detecting mosquito-borne viruses (dengue, and most recently Zika).

Field Assisted Sintering of Ceramics

 One set of sintering techniques that has produced promising results in multiple systems utilizes electrical currents to aid densification, either by heating the sample or surrounding dies with resistive heating at high rates of above 100oC/min in a technique commonly called Spark Plasma Sintering (SPS), or through a much broader range of techniques, which apply a voltage exclusively to the sample during sintering, referred to as field assisted sintering (FAST). FAST sintering techniques (e.g. FLASH sintering) are less developed than SPS, but possess the advantage of not requiring expensive vacuum equipment or sample-contaminating graphite dies. To isolate the effect of the electric field itself on microstructure and electronic properties outside of the context of SPS, we designed a apparatus similar to the FLASH sintering  that is able to decouple the applied voltage from the system temperature. We aim to expand the ability to control microstructure development and thus electronic properties of ceramics, such as solid state battery materials, and possibly open new routes to sintering bulk solid state batteries with advantageous properties.

 One set of sintering techniques that has produced promising results in multiple systems utilizes electrical currents to aid densification, either by heating the sample or surrounding dies with resistive heating at high rates of above 100oC/min in a technique commonly called Spark Plasma Sintering (SPS), or through a much broader range of techniques, which apply a voltage exclusively to the sample during sintering, referred to as field assisted sintering (FAST). FAST sintering techniques (e.g. FLASH sintering) are less developed than SPS, but possess the advantage of not requiring expensive vacuum equipment or sample-contaminating graphite dies. To isolate the effect of the electric field itself on microstructure and electronic properties outside of the context of SPS, we designed a apparatus similar to the FLASH sintering  that is able to decouple the applied voltage from the system temperature. We aim to expand the ability to control microstructure development and thus electronic properties of ceramics, such as solid state battery materials, and possibly open new routes to sintering bulk solid state batteries with advantageous properties.

Resorbable metals for transient orthopedic devices

So far, the field of prosthetics has been relying on polymers and stainless steels, while using bioresorbable nutrient metals is a novel, much less explored idea that brings together the advantages of combining the mechanical strength necessary for initial support with the capacity of resorption after tissue remodeling. The impact of porosity and surface chemistry on the initial cell adhesion and tissue ingrowth, which in turn affects the speed and quality of tissue modeling and remodeling, cannot be overstated.  Bioresorbable metals (Mg-alloys, Fe-Mn alloys) have the potential to yield implants for clinical applications requiring only transient structure, ideally resulting in well-healed native tissues.  Imagine having bone pins used to fix bone fracture that will never have to be removed because they will resorb and dissapear within 1-2 years. We perform the structure-properties studies on Fe-Mn based bioresorbable materials toward the control of resorption (corrosion) rate, biocompatibility, cell adhesion and mechanical strength.

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