"One of our leading researchers has developed an amazing new material that has shown excellent creep and fatigue properties under extreme testing conditions. Consequently it has attracted great interest from a number of commercial parties, all wanting to exploit the improved mechanical integrity it could offer their products. But then, while working late in the lab one night, the inventor is murdered and all the data and specimens are stolen. Industrial espionage is suspected.
Several key pieces of evidence are recovered from the scene. CCTV footage reveals the murder weapon to be a spanner, which the suspect is seen wiping clean to remove any incriminating fingerprints. Metal filings are recovered from the floor near the body and a fibre from the suspect's clothing is picked up on the door lock. Samples of the sign-in book for the building are taken for ink analysis and several items from within the laboratory are taken away for fingerprinting..."
This is a scenario we've set up at Swansea University's Materials Research Centre to bring the popularity of programmes like Crime Scene Investigation (CSI) to the world of materials science. Our aim is to galvanise and engage the interests of 11-18 year olds who are the materials scientists of tomorrow. To solve our fictional crime, participants receive an evidence pack containing samples of the material collected at the crime scene together with information on some potential suspects.
|Scanning Electron Microscopy (SEM) forms images with electrons rather than light. Smaller wavelength means you can image smaller features, and at higher resolution.|
Traditional imaging optical microscopes allow magnifications up to 2000X, whereas SEM can image up to 1000000X.
Using the techniques and resources available within the University's Materials Research Centre they then systematically deduce which suspect is most likely to have committed the crime. Each suspect has a background in a different metals industry, therefore scanning electron microscopy and energy dispersive x-ray analysis will link the metal filings found at the scene to some of the suspects, depending on the microstructure and elemental compositio
|Fourier Transform Infra-Red Spectroscopy (FTIR) measures the infra-red vibrational response of most carbon-based materials.|
The way a material absorbs infra-red is characteristic of certain compounds, which FTIR can be used to identify.
Fourier transform infrared spectroscopy (FTIR) will connect the retrieved fibre to a perpetrator's pants, while pens taken from each of the suspects will be analysed using chromatography to establish who signed the laboratory guest book. A historical method of revealing latent fingerprints is also employed on the book using a silver nitrate-ethanol solution. Applied to the paper and allowed to develop under ultraviolet light, the silver nitrate reacts with sodium chloride left by evaporated perspiration to produce silver chloride. This is revealed as a reddish-brown or black "dab".
A second method of disclosing latent fingerprints is applied to the plastic phials removed from the laboratory. Cyanoacrylate, the active ingredient in superglue, when heated, produces a cyanoacrylate monomer vapour. This vapour reacts with the residues left by a fingerprint and polymerises to a white polymer (polycyanoacrylate), revealing the ridges and folds of a print.
The final forensic process employed during the activity is a method of visualising latent fingerprints on metallic and electrically conductive surfaces without the need to develop the prints first, a technique recently developed by electro-chemists at Swansea. This method is applied to the spanner found at the scene and involves the use of an instrument called the scanning Kelvin probe (SKP). This measures the voltage, or electrical potential, at pre-set intervals over the surface of an object on which a fingerprint may have been deposited. These voltage measurements can then be mapped to produce an image of the fingerprint.
By the end of the activity the students will have gained hands-on experience of exciting forensic methods within a University laboratory environment. We hope that this activity will raise awareness among participants of materials science and its role within not only criminal forensics but also forensic engineering, investigating failures of engineering components and how new materials can drive modern industry forward. The ultimate aim is to inspire the next generation of materials scientists and engineers.
We've also extended the activity to include regular visits to local schools and colleges to preach the "Structural Metals" message. We recently acquired a small-scale gas turbine which was purchased with the aid of the EPSRC's "Pathways to Impact" initiative. These models help audiences of all ages to grasp the engineering challenges that must be overcome to deliver future generations of jet engines, and the central role played by the materials sciences in that process.
Our longer-term game plan is to see that, once recruited onto engineering-based study, undergraduates and graduate students will be able to exploit the long-established links between the Swansea-Birmingham-Cambridge University Technology Partnership (UTP) in Materials, and Rolls-Royce offer a structured career path into the aero-engine industry from the earliest stages of the undergraduate degree programme.
The top performing materials engineering undergraduates are awarded industrial bursaries, and have the opportunity to undertake project work linked to major research contracts within the UTP. Students are exposed to an active research environment with direct industrial relevance, giving them a taste of what an engineering and manufacturing-relevant EngD or PhD project entails. This puts postgraduate students in the shop window for careers at Rolls-Royce and their supply chain partners. Postgraduate projects linked to these industrial partners often results in the student becoming a world-leading expert in their field and, through the Strategic Partnership Doctoral Training Partnership developing a strong professional and managerial grounding.
So, by harnessing the current interest in the world of CSI, Swansea UTC is helping to deliver the Materials Engineers of the future.