This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Computed tomography (CT) is the 3D-reconstruction of projections of an object viewed from different directions. CT non-destructively generates a fully 3D model of samples that allows many possibilities for analysis: the non-destructive visualization of slices (a very powerful aspect), arbitrary sectional views, pseudo-color representations and pore analysis. Technological advances have led to progressive improvements in CT resolution and accuracy. In the past, synchrotron radiation-based microCT (SRìCT) has been the high resolution technique of choice. Nanotomography (nanoCT), a recently developed technique, exploits X-ray sources with sub-ìm focal spot size to yield spatial resolutions down to 200-300 nm. NanoCT enables a large range of applications ranging from low-absorbing biological samples to high-absorbing metal objects such as metallic implant materials. The proposed system provides room for future expansion to design and incorporate appropriate accessories for high-resolution in situ visualization of material behavior in in vivo environmental conditions, as dictated by research findings.
The vision of NCAT's NSF ERC-RMB is to revolutionize metallic biomaterials and underlying sciences and technologies, leading to engineered systems that will interface with the human body to prolong and improve quality of life, coupled with the development of a vibrant, diverse workforce well-prepared for the multidisciplinary and global challenges and opportunities of the new millennium. The mission is to deliver on the potential of bio/nanoengineering to dramatically improve treatments for orthopedic, craniofacial and cardiovascular ailments. The goal is to develop new implant materials and tunable biodegradable metals that can grow and adapt to the human body and eventually dissolve when no longer needed.
North Carolina A&T State University (NC A&T) was awarded an NSF MRI-R2 equipment grant with which it purchased a state of the art X-ray computed tomography (CT) machine, GE Instruments Phoenix Nanotom-M. The ability to see inside of objects is most commonly experienced at a medical or dental facility in the form of X-rays. The computed tomography application of x-rays differs in that 100s or 1000s of x-rays of a given object from different reference points are taken, generally encompassing a 360° sweep of the object. Sophisticated computer algorithms then process these images and create a computer image of the object with which the researcher can probe inside and out utilizing software. The advantages to looking into materials and devices in this non-destructive fashion are numerous and again have great similarity to the benefits of medical applications of x-rays. It is good that the medical professional can determine the health and integrity of a bone using a picture rather than having to do exploratory surgery, and this benefit shines in materials science. Of particular importance to NC A&T and the research efforts stemming from its NSF sponsored Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB) is the ability of this instrument to probe materials that have been implanted into living tissues. The ERC-RMB is exploring substitutes for titanium implants, used in bone fixation for example, and has focused on metals whose corrosion rate can be controlled and which the body has natural metabolic pathways for excretion. Magnesium is a key focus of this research and the Nanotom-M CT has allowed researchers to probe medical devices made of magnesium that have been implanted into tissues. By comparing before implant images with images of the devices exposed to tissues and biological environments, quantitative models for magnesium corrosion can be formulated that then can lead to more optimal magnesium alloy design. The Nanotom-M at NC A&T has been used in many other applications including the imaging of composite materials such as carbon fibers and fiberglass and devices such as batteries. The Nanotom-M is a unique machine that is making a real impact for good within and without the NC A&T community through educational and industrial outreach. We have discussed several projects with local businesses including the imaging of coating thicknesses. A series of images was created for educational outreach endeavors that included CT scans of fruit, toys and insects. This research so far has been presented twice and participants included high school and community college educators, local professional society members, and the NC A&T student population. It is expected that the positive impact of this machine and its capabilities will expand as we continue to apply its unique capabilities to research, education, and community partnerships.
