Tag Archives: atomic force microscope

5,000 year old blood analyzed with an AFM (atomic force microscope)

They’ve been able to recover blood from the 5000 year old Iceman Mummy and answer a question regarding his (Ötzi’s) death according to the May 8, 2012 news item on Nanowerk,

His DNA has been decoded; samples from his stomach and intestines have allowed us to reconstruct his very last meal. The circumstances of his violent death appear to have been explained. However, what had, at least thus far, eluded the scientists, was identifying any traces of blood in Ötzi, the 5,000 year old glacier mummy. Examination of his aorta had yielded no results. Yet recently, a team of scientists from Italy and Germany, using nanotechnology, succeeded in locating red blood cells in Ötzi’s wounds, thereby discovering the oldest traces of blood to have been found anywhere in the world …

The research paper “Preservation of 5300 year old red blood cells in the Iceman” ([free access] Interface: Journal of the Royal Society) written by Marek Janko, Robert W. Stark, and Albert Zink helps outsiders like me better understand why there is excitement about finding blood, from the Introduction to the paper (footnotes have been edited out),

Examining mummies with sensitive analytic tools enables the reconstruction of their ancestry and genetic relationships, diet, diseases, living conditions, state of preservation and the mummification processes. While many studies provided molecular evidence for the presence of infectious diseases in ancient populations, leading to deep insights into the evolution of such diseases, only a few reports on the recovery of blood from mummified bodies are available. Previous investigations, based on optical or electron microscopy data, postulated that blood remains or fragments could be preserved in mummies as old as 2000 years. [emphases mine] Although molecular verification of blood findings was not performed, detection of blood components was of major interest because it could give new perspectives on the lives and fates of our ancestors. Blood can indicate the general health status of an individual and it can be analysed to detect pathological conditions or to provide valuable information in forensic crime scene investigations.

So finding blood in the 5000 year old Iceman Mummy means this sample is more than double the age of previous samples. It also answers a question about his death, from the May 8, 2012 news item on Nanowerk,

Whilst examining the wound at the point where the arrow entered the body, the team of scientists also identified fibrin, a protein involved in the clotting of blood. “Because fibrin is present in fresh wounds and then degrades, the theory that Ötzi died some days after he had been injured by the arrow, as had once been mooted, can no longer be upheld,” explains Albert Zink.

They used an atomic force microscope for part of this project,

The team of scientists used an atomic force microscope to investigate thin tissue sections from the wound where the arrow entered Ötzi’s back and from the laceration on his right hand. This nanotechnology instrument scans the surface of the tissue sections using a very fine probe. As the probe moves over the surface, sensors measure every tiny deflection of the probe, line by line and point by point, building up a three-dimensional image of the surface. What emerged was an image of red blood cells with the classic “doughnut shape”, exactly as we find them in healthy people today.

Here’s an image of the blood,

5,000 year old red blood cells discovered. Oldest blood known to modern science. Credit: EURAC

This finding, as exciting as it is from an historical perspective, also hints at possible future applications for modern forensic science, from the May 8, 2012 news item on Nanowerk,

“Up to now there had been uncertainty about how long blood could survive – let alone what human blood cells from the Chalcolithic period, the Copper Stone Age, might look like.” This is how Albert Zink, Head of the Institute for Mummies and the Iceman at the European Academy, Bozen-Bolzano (EURAC) explains the starting point for the investigations which he undertook with Marek Janko and Robert Stark, materials scientists at the Center of Smart Interfaces at Darmstadt Technical University.

Even in modern forensic medicine it has so far been almost impossible to determine how long a trace of blood had been present at a crime scene. Scientists Zink, Janko and Stark are convinced that the nanotechnological methods which they tested out on Ötzi’s blood to analyse the microstructure of blood cells and minute blood clots might possibly lead to a break-through in this area.

EURAC’s Institute for Mummies and the Iceman is rather interesting, from the Institute for Mummies and the Iceman webpage,

The EURAC-Institute for Mummies and the Iceman gathers and coordinates all currently available scientific data on the Iceman and various other mummies.
Founded in 2007, it also supplies new impulses for anthropological, palaeopathological, genetic and medical research. In addition, it promotes innovative techniques for mummy conservation.

The EURAC-Institute for Mummies and the Iceman strongly supports and promotes the use of non-and minimal invasive investigation methods, such as computer tomography, nanotechnology, molecular and biological approaches, as well as ancient DNA research.  It collaborates with several renowned universities and museums worldwide.

The creation of a mummy research centre in Bolzano was generally welcomed, in particular by those who were more or less directly involved with studies on the Iceman, not least because the EURAC-Institute for Mummies and the Iceman assures optimal conservation conditions for the mummy.

One of the EURAC-Institute for Mummies and the Iceman’s tasks is gathering all available scientific data on the Iceman. This includes archaeological site material, as well as papers, notes, documentation material from research groups from all over the world.

The Iceman was found in 1991 in the Alps and is the oldest wet mummy ever discovered (dated 3.300-3.150 BC). He spent seven years in Innsbruck (A) thereafter, where he was extensively studied at the Research Institute for Alpine Prehistory. Meanwhile, the South Tyrolean Museum of Archaeology was established in Bolzano and a specially designed refrigerating chamber was created in order to preserve this unique mummy. In 1998, once the mummy had been moved to Bolzano, the Research Institute for Alpine Prehistory in Innsbruck was closed and all studies concerning the Iceman were carried out at different Universities.

That excerpt from the Institute’s webpage was a bit off tangent but I do find the “specially designed refrigerating chamber” a rather intriguing detail.

Back to my roots, writing nanotechnology

This July 18, 2011 news item title, Writing Nanostructures: Heated AFM Tip Allows Direct Fabrication of Ferroelectric Nanostructures On Plastic, on the Science Daily website brought back memories. The first part of the title, Writing Nanostructures, that is. My first project about nanotechnology and the language used to describe it for my master’s degree was titled, Writing Nanotechnology.

This, of course, is something entirely different. From the news item on Science Daily,

Using a technique known as thermochemical nanolithography (TCNL), researchers have developed a new way to fabricate nanometer-scale ferroelectric structures directly on flexible plastic substrates that would be unable to withstand the processing temperatures normally required to create such nanostructures.

The technique, which uses a heated atomic force microscope (AFM) tip to produce patterns, could facilitate high-density, low-cost production of complex ferroelectric structures for energy harvesting arrays, sensors and actuators in nano-electromechanical systems (NEMS) and micro-electromechanical systems (MEMS). The research was reported July 15 in the journal Advanced Materials.

“We can directly create piezoelectric materials of the shape we want, where we want them, on flexible substrates for use in energy harvesting and other applications,” said Nazanin Bassiri-Gharb, co-author of the paper and an assistant professor in the School of Mechanical Engineering at the Georgia Institute of Technology.

I particularly like this picture where the professor is holding something that looks like a pencil as a pointer,

Georgia Tech postdoctoral fellow Suenne Kim holds a sample of flexible polyimide substrate used in research on a new technique for producing ferroelectric nanostructures. Assistant professor Nazanin Bassiri-Gharb points to a feature on the material, while graduate research assistant Yaser Bastani observes. (Credit: Gary Meek)

You can check out the rest  in the Science Daily news item or you can check out the original Georgia Institute of Technology news release (which has more images) written by John Toon.

 

Scientific research, failure, and the scanning tunneling microscope

“99% of all you do is failure and that’s maybe the most difficult part of basic research,” said Gerd Binnig in a snippet I’ve culled from an interview with Dexter Johnson (Nanoclast blog on the IEEE [Institute of Electrical and Electronics Engineers] website) posted May 23, 2011 where Binnig discussed why he continued with a project that had failed time and time again. (The snippet is from the 2nd audio file from the top of the posting)

Binnig along with Heinrich Rohrer is a Nobel Laureate. Both men won their award for work on the scanning tunneling microscope (STM), which was the project that had failed countless times and that went on to play an important part in the nanotechnology narrative. Earlier this month, both men were honoured when IBM and ETH Zurich opened the Binnig and Rohrer Nanotechnology Center in Zurich. From the May 17, 2011 news item on Nanowerk,

IBM and ETH Zurich, a premiere European science and engineering university, hosted more than 600 guests from industry, academia and government, to open the Binnig and Rohrer Nanotechnology Center located on the campus of IBM Research – Zurich. The facility is the centerpiece of a 10-year strategic partnership in nanoscience between IBM and ETH Zurich where scientists will research novel nanoscale structures and devices to advance energy and information technologies.

The new Center is named for Gerd Binnig and Heinrich Rohrer, the two IBM scientists and Nobel Laureates who invented the scanning tunneling microscope at the Zurich Research Lab in 1981, thus enabling researchers to see atoms on a surface for the first time. The two scientists attended today’s opening ceremony, at which the new lab was unveiled to the public.

Here’s an excerpt from Dexter’s posting where he gives some context for the audio files,

As promised last week, I would like to share some audio recordings I made of Gerd Binnig and Heinrich Rohrer taking questions from the press during the opening of the new IBM and ETH Zurich nanotechnology laboratory named in their honor.

This first audio file features both Binnig’s and Rohrer’s response to my question of why they were interested in looking at inhomogenities on surfaces in the first place, which led them eventually to creating an instrument for doing it. A more complete history of the STM’s genesis can be found in their joint Nobel lecture here.

The sound quality isn’t the best but these snippets are definitely worth listening to if you find the process of scientific inquiry interesting.

For anyone who’s not familiar with the scanning tunneling microscope, I found this description in the book, Soft Machines; Nanotechnology and Life, by Richard Jones.

Scanning probe microscopes rely on an entirely different principle to both light microscopes and electron microscopes, or indeed our own eyes. Rather than detecting waves that have been scattered from the object we are looking at, on feels the surface of that object with a physical probe. This probe is moved across the surface with high precision. As it tracks the contours of the surface, it s moved up or down in a way that is controlled by some interaction between the tip of the probe and the surface. This interaction could be the flow of electrical current, in the case of a scanning tunneling microscope, or simple the force between the tip and the surface in the case of an atomic force microscope. pp. 17-18