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Fleming to Lead New Research with Highly Specialized Instrument


JONESBORO – Measuring materials and biological specimens at the smallest scale will be possible with highly specialized laboratory equipment being acquired in the College of Engineering and Computer Science at Arkansas State University.

Dr. Robert (Drew) Fleming, assistant professor of mechanical engineering, is principal investigator (PI) for a recent grant to A-State from the National Science Foundation (NSF). Fleming’s proposal for approximately $580,000 through NSF’s Major Research Instrumentation (MRI) Program was approved, clearing the way to acquire a nanoindenter, which conducts materials science and biomaterials research.

“This tool will support research on mechanical characterization of nanomaterials, dental caries-affected teeth, cardiac cells and tissues, advanced paving materials, nano-engineered surfaces, and semiconductor quantum dots,” Fleming noted, emphasizing the broad spectrum of materials that can analyzed.

Due to its unique nature, the nanoindenter is being custom built. After the final order was placed in November, he expects it will be installed in his A-State lab and commissioned by May of next year.

A nanoindenter is used to measure the mechanical properties of materials at the “nanoscale.”  The award also includes specialized testing capabilities for performing experiments on biological tissues at physiological conditions. This feature was developed by Brüker, the manufacturer, as part of their special product request program; this is the first such tool Brüker produced to feature this functionality.

Co-principal investigators on the award are Dr. Robert Shields, assistant professor of microbiology, Dr. Zahid Hossain, professor of civil engineering, Dr. Ilwoo Seok, associate professor of mechanical engineering, and Dr. Paul Minor, assistant professor of electrical engineering, along with Dr. Viswanathan Rajagopalan of New York Institute of Technology College of Osteopathic Medicine at A-State.

“I appreciate your leadership in winning this prestigious MRI grant for the acquisition of a nanoindenter,” Dr. Abhijit Bhattacharyya, dean of the College of Engineering and Computer Science, told Fleming. “This will be a game changer for materials research in our university and the region. Congratulations to you and your team of co-PIs.”

Fleming explained that a nanoindenter is a tool for characterizing mechanical properties of materials, primarily elastic modulus and hardness, by measuring how the material deforms when a sharp diamond indenter is pressed into the material.

The nanoindenter being acquired through the grant will have special testing capabilities, Fleming added.

“Most nanoindenters can only reliably measure ‘hard’ materials like metals. This one has been specially configured to also measure ‘soft’ materials, like biological tissues, in a controlled environment that mimics physiological conditions,” Fleming explained. “The main benefit is that this tool can make these measurements with very small forces and deformations, as compared to a standard macro scale tensile test which would require deforming the specimen until it breaks.”

Nanoscale refers to length measured in units of nanometers.  For instance, there are 1,000 millimeters in a meter, 1,000 micrometers in a millimeter, and 1,000 nanometers in a micrometer – meaning one nanometer is one-billionth of a meter.  For reference, the width of a human hair is about 100 micrometers, so a nanoscale measurement happens on a length scale that is many times smaller.

“The nanoindenter can measure the properties of bulk materials without destroying them, but can also measure very small objects like nanoparticles and individual cells,” the engineering professor continued. “It can also measure the mechanical properties of composite materials that do not have uniform mechanical properties across the sample.”

The nanoscale resolution of the nanoindenter means that it can make a mechanical property measurement on a very small volume of materials.

“For biological materials like teeth and cardiac cells, measurements of the mechanical properties of these materials in response to disease can provide insights into changes in the materials happening at the biological level, which can be associated with the genetic origins of the disease,” he also said.

Dr. Robert (Drew) Fleming