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Category: ESM News
Posted by: emg5174 on Mar 31, 2014
(Nanowerk News) Latent fingerprints - which cannot be seen without the application of a chemical or physical treatment - are among the most common forms of evidence used to link criminals to a crime scene and provide the proof needed to convict them. However, traditional methods for developing fingerprints (i.e. making them visible), may be inadequate when dealing with latent prints on nonporous surfaces such as knife handles, doorknobs, and garbage bags. A poorly developed print may lead to a wrong identification or no identification at all, putting an innocent person behind bars or missing an opportunity to catch the real perpetrator.

In a new paper in the Journal of Vacuum Science and Technology B ("Quality of development of latent sebaceous fingerprints coated with thin films of different morphologies"), a research team at Penn State University describes a development method using columnar thin films (CTF) that is quick, provides a high level of detail and resolution, and yields consistent results on prints recovered from many types of nonporous surfaces.

A latent fingerprint contains secretions from both the sebaceous and eccrine glands in the palms. Eccrine secretions are 98 percent water, so over time they will evaporate or become absorbed by other components of the fingerprint. Therefore, a slightly aged print is left primarily with only sebaceous materials (saturated fats, waxes and a hydrocarbon called squalene). To visualize sebaceous secretions, they have to be treated. Standard methods include applying a powder, coating with chemicals (such as ninhydrin and 1,8-diafluorene to react with amino acids or silver nitrate to react with chloride ions) or fuming with cyanoacrylate (the active ingredient in "super glues"). Unfortunately, these methods are not versatile enough.

To remedy the problem, three engineers at Penn State University - Akhlesh Lakhtakia and two of his doctoral students, Steve Swiontek and Drew Pulsifer (now at Intel) - deposited a columnar thin film on top of latent sebaceous fingerprints. "The CTF is an assemblage of nanoscale upright columns that capture the detail of a print's friction ridges [the raised layers of skin that define the print]," Lakhtakia says.

"To understand how it works, imagine putting your hand palm-side up on a table and standing identical pieces of chalk vertically upon the skin until the surface was completely covered. The tops of the chalk pieces would reproduce the shape of the palm, with the resolution of the 'image' increasing as you use smaller and smaller diameter chalk."

With the CTF print development method, the "chalk pieces" are infinitesimally small with the columns measuring approximately 60 nanometers (60 billionths of a meter, about half the size of an influenza virus) in diameter. This, Lakhtakia says, allows them to conform very tightly to the valleys and ridges of a fingerprint. "The coated print can easily be seen by the naked eye and its optical image manipulated by specialized software to yield forensically relevant data," he says.

Using a sophisticated computer analysis system, the Penn State team assessed the quality of fingerprints developed with the CTF method and compared the results to those achieved via traditional methods. CTF-processed prints were as good or better for most nonporous substrates tested. The researchers also found that the CTF method appears to be particularly suitable for developing partial bloody fingerprints, for which standard techniques are ineffective.

Finally, Lakhtakia and his students studied what happened if the columns were slanted instead of straight, and if the CTF was replaced by a dense homogenous layer. In both cases, the visualization quality of the treated fingerprints was significantly reduced.

With the validity of the CTF fingerprint development method established, the researchers will now seek funding for trial programs to see if crime laboratory personnel can be trained to use it. They also plan to investigate how environmental insults - such as prolonged exposure to moisture, dryness, high and low temperatures, etc. - impact the effectiveness of the CTF technique.

Source: AVS
Posted by: emg5174 on Mar 27, 2014
Engineering science undergraduate student Veronica Sardo participated as a student representative in the International Society for Optics and Photonics’ (SPIE) “Biomimicry, Bioinspiration, and the San Diego Zoo” panel discussion, held March 12 in San Diego as part of Smart Structures/Nondestructive Evaluation (SS/NDE) week.

SPIE and the SS/NDE symposium partnered with the San Diego Zoo to organize a panel to promote the value of biomimicry as a paradigm for engineering research and practice. Biomimicry is designing and producing materials, structures, and systems that are modeled on biological entities and processes. The panel focused on all aspects of engineered biomimicry, including education, awareness, applications, research, and funding sources.

A senior education guide from the zoo presented an anteater named Tipu to provide a focal point for the discussion. Other panel members included representatives from the U.S. Forest Service, NASA Johnson Space Center, nanoscience research center CIC nanoGUNE Consolider, University of Sheffield, and Osaka University. The panel moderators were Akhlesh Lakhtakia, the Charles Godfrey Binder Professor in Engineering Science and Mechanics at Penn State and Gabriel Miller, Director of Research and Development for the San Diego Zoo’s Centre for Bioinspiration.

Read more about the panel's discussion in the SPIE SS/NDE event news article, "Bioinspiration, courtesy of Tipu."
Category: Engineering News
Posted by: emg5174 on Mar 19, 2014
Registration is now open for the 18th Annual Corrosion Short Course at Penn State.

The course will cover the fundamentals of corrosion and various electrochemical techniques. Lectures and laboratories will be used to illustrate how electrochemical techniques are applied, when they should be used, and how the various techniques can be integrated to solve complex problems. The course will be useful for people entering the corrosion field and for professionals looking for a refresher course.

Click here for more information.
Posted by: emg5174 on Mar 14, 2014
Professor Melik Demirel has been invited to give a lecture at the Hydrophobic Surfaces Symposium at the American Chemical Society (ACS) National Meeting & Exposition in Dallas, March 16-20. Dr. Demirel's talk will explore the asymmetric wetting, transport, and adhesion properties of elastomeric materials extracted from squid ring teeth and discuss how these properties vary across different squid species.

The 247th ACS National Meeting & Exposition, Chemistry and Materials for Energy, will host more than 12,000 chemical professionals.

Posted by: emg5174 on Mar 4, 2014
Professor Michael Lanagan will visit the Department of Physics at the University of Houston on March 5 to discuss "High Energy Dielectrics for Pulse Power and Power Electronic Applications."

Pulsed power and power electronic systems are found throughout our society and today they continue to appear in applications such as heart defibrillators and hybrid electric vehicles. The primary focus of the seminar is to assess current dielectric material and component technologies and determine critical technology gaps for implementation of capacitors in power electronic converters and pulsed power applications. Glass and inorganic/organic composite materials are particularly attractive for power electronic and pulsed power applications because high energy density can be achieved with scalable manufacturing processes. The challenge can be distilled into a single figure-of-merit, energy density, which captures the vital materials parameters of relative dielectric permittivity and dielectric breakdown strength. In addition to energy applications, dielectrics play an important role in metamaterial structures for high frequency applications and all-dielectric concepts will be presented which go beyond traditional metal rings and wire arrays.
Posted by: emg5174 on Mar 3, 2014
The 11th annual ESM graduate research symposium, ESM Today, was held March 1. The symposium is open to all graduate students in the department and an opportunity to share research with peers and faculty. This year's keynote speaker was alumnus and ESM faculty member Dr. Stephen Fonash ('63 E SC), the Bayard D. Kunkle Chair of Engineering.

Congratulations to the ESM Today 2014 winners:

Room 114
1st Aniruddh Vashisth, Shape and Stiffness-Changing Stuctures based on Fluidic Flexible Matrix Composites
2nd Cooper Elsworth, Validation and Verification of an Overset Fluid-Structure Interaction Solver
3rd Stephen Swiontek, Optical Sensing Via Surface Multiplasmonics

Room 116
1st Ahmad Ahsan, Red Blood Cell and Platelet Count of Newborns Via Microfluidic Drifting Flow Cytometry
2nd Aaron Lesky, Wave Energy as a Damage Sensitive Feature
3rd Abdon Francesh, Materials Fabrication from Squid Ring Teeth Proteins

Poster Competition
1st Aniruddh Vashisth, Shape and Stiffness-Changing Stuctures based on Fluidic Flexible Matrix Composites
2nd Maryam Neshastehriz, Microstructures of Ball Milled hBN-Ni Cold-Sprayed onto an Aluminum Substrate
3rd Cooper Elsworth, Validation and Verification of an Overset Fluid-Structure Interaction Solver
3rd Hui Yang, Lithiation-Induced Self-Weakening in Carbonaceous Nanoelectrodes