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 Issue # 5
Nov 2009
 
Nano Torsion Probes for the Atomic Force Microscope (AFM)

By Dr. Arthur Beyder, Marianne Timm

principle of AFM operationFigure 1 illustrates the principle of AFM operation: an ultra-sharp tip (radius of curvature ~50nm) is rastered over the surface of a sample and force exerted by the sample on the tip is transduced through bending of a microscale cantilever. Cantilever movement is typically monitored by a focused laser beam reflected off the cantilever (optical lever) onto a position sensitive photodetector (PSPD). Similar in function to a record player, the AFM reads the topography of the sample showing a different image from a traditional "microscope" and is capable of visualizing nanometer features. The direct nature of this instrument's interaction with the sample allows nanoscale manipulations, such as molecular nanosurgery.    

The atomic force microscope was developed for measuring hard, dry surfaces, such as semiconductors, and achieves its best resolution in vacuum at the lowest possible temperature and minimal thermal noise.  Yet, the ability of the AFM to measure forces in single molecules and cells makes the AFM attractive to biologists. However, biological samples, such as living cells are extremely soft and work best at body temperature in saline solution, limiting AFM resolution. First, cells are roughly 1000 times softer than the softest available cantilevers, limiting cantilever bending. Second, the saline solution increases viscous drag on the cantilever reducing its frequency response compared to its operation in air or vacuum. This results in a cantilever that is slow and heavy-footed. Third, commercially available cantilevers are often biomorphs that may warp in liquids and high temperatures.   

AFM sensitivity is limited by cantilever sensitivity, i.e., how much the angle changes with a given force. The established method for increasing cantilever compliance (sensitivity) is to increase cantilever length while keeping its thickness constant. However, a long cantilever in saline solution has more surface area and hence more viscous drag and a lower frequency response. Accordingly, this method is suboptimal for increasing AFM sensitivity in the measurement of biological samples. 

nano torsion probeDoctors Arthur Beyder and Frederick Sachs working at the Center for Single Molecule Studies at the University of Buffalo solved these problems by creating the patented, Nano Torsion Probe, which is illustrated in figure 2. This probe minimizes the problems of the atomic force microscope for biological samples by utilizing <100nm torsion hinges (SiN) and decreasing the moving block area (Si). The small size of the mirrored block (~ 20x20 μm) minimizes the viscous drag. The torsion hinges allow the probe to only move in one axis (rotation), making the interpretation of the data simpler than a cantilever, which can twist and bend. Thin hinges allow for a decrease in spring constant and a decrease in moving area resulting in high resonant frequency, and a lower viscous drag as well as an increase in optical lever gain. These benefits help to further improve the signal to noise ratio. Additionally, the symmetrical design of the Nano Torsion Probes greatly reduces temperature and solution induced warping. Accordingly, AFMs with the Nano torsion probe are optimal for investigation of soft samples in viscous environments and provide higher compliance and frequency response. Not only are these probes optimal for soft samples in viscous environment, but they are 10-fold softer, 10-fold faster, and 100-fold more sensitive than traditional cantilevers. Furthermore, the Nano Torsion Probe can be used in place of traditional cantilevers with little or no change in cost. 

Nano Torsion Probes allow scientists to get more data from the same experiment with no additional effort or cost. This increased sensitivity allows for the exploration of new frontiers in biology. Trial samples of single axis Nano Torsion Probes are available. For more information regarding this patented technology, contact Dr. Arthur Beyder or Dr. Frederick Sachs.


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Recap of MN Nano's 2009 Legislative Session efforts

By Lynne Osterman, Shweta Sharma

MN Nano has supported and advocated at the Minnesota Legislature for the creation of the North Star Rising (NSR), the progress and outcome of which resulted in the formation of what is called the State Science and Technology Strategy Committee. What follows is a recap of MN Nano's 2009 Legislative Session efforts and where things are now in terms of the "S&T Strategy Committee."
 
State Science & Technology Strategy Committee
What do you do if people come to you year after year with somewhat related ideas, approaches, suggestions, solutions, mechanisms, opinions, concepts, rationales, objectives and the like? Sometimes, paralysis occurs. Actually, it's human nature. When faced with a myriad of ideas to the point where it feels like, "Well, we've got to do something, so let's do this...," you toss a dart toward the awaiting board, a dart that in its wisdom is about to select out of the seemingly hundreds of ideas, a dart that lands on: Number 69 on the Priority List. But in the absence of a priority list, we go with the random choice our dart has selected for us.
 
In the case of tech-based economic development, however, a state can't be competitive by throwing darts at a board to see what sticks. In the case of tech-based economic development, Minnesota cannot be competitive without a priority list. The problem is, Minnesota cannot even agree as to how the priority list should be made in the first place. Rather, we've grown accustomed to the annual pilgrimage to the Minnesota Legislature and Governor Pawlenty for the past eight years, asking them to throw the darts to whittle down the options and then with sometimes arguably little regard to long-term viability or lasting impact (think "bio-zones"), something might get passed. 
 
The Priority List
The absence of a priority list - so ideas can be evaluated and ranked as they are pulled out of the Suggestion Box - has plagued our state long enough. At least that is what a collection of people from the science & technology community believe. In 2008, two reports* were commissioned which, upon release, had a number of findings in common. A major conclusion from both indicated that Minnesota's lack of a tech-based economic development strategy had become a liability to the state's competitive ability. When compared to where other states (& countries) are likely to be even a mere 10 years from now, by leveraging their respective long-term plans, the studies predict, Minnesota is going to be lagging far behind.
 
The science and technology community proposed the creation of the NSR, a statewide commission-of sorts, that would have the responsibility for creating a visionary, comprehensive, attainable and measurable tech-based economic development strategy for the North Star State. NSR objectives would include:
  • Establish the tech-based economic development strategy against which the aforementioned annual myriad of Suggestion-Box approaches would be evaluated.
  • Benchmarking and evaluation responsibilities to be sure goals & objectives were actually achieved, results measured and shared.
  • Assist the legislature, the governor, the state employees working with economic development programs, municipalities and regions in determining, implementing and evaluating priority programs and activities in light of the over-arching tech-based economic development strategy.
Crawl before you walk
Like all good tales of the twists and turns seemingly brilliant legislative proposals have in their wake, the NSR proposal had a couple things going against it by the time the 2009 Legislature convened in January.  First, the NSR proposal was not in full bill form for legislative introduction and committee discussion at the outset of the 2009 Session. Second, due to the first, there was no public discussion about the absence of a Priority List, so the Annual Pilgrimage to St. Paul with a myriad of ideas out of the Suggestion Box was in Full Swing by the time the NSR concept was on the table (with some of the ideas building up steam and burning political capital, an irrefutable repercussion).
 
The net outcome of the original NSR legislation was the creation of a public-private project, with the underlying hope the said group would eventually recommend a structure to be given the responsibility and accountability for all of the deliverables previously noted for the NSR entity. The legislation passed in May 2009 stated the Commissioner of the Department of Employment shall lead a public-private project to advise state agency collaboration to design, coordinate, and administer a strategic science and technology program for the state designed to promote the welfare of the people of the state, maximize the economic growth of the state, and create and retain jobs in the state's industrial base and [report back to the Legislature] by January 15, 2010 on the activities of the project and must recommend changes or additions to its organization, including specific recommendations for necessary legislation.**
 
Coined by DEED Commissioner Dan McElroy the "Science and Technology Strategy Committee"(STSC), the group first convened on October 6 and has two other meetings scheduled before the end of the year. Since the group has met only once, it might seem premature to predict an outcome.
 
Prediction: The outcome of the STSC will be:
  • No comment on the design of a strategic S&T program for the state that would create a roadmap for Minnesota tech-based economic development.
  • Another litany of individual suggestions to the legislature for the 2010 Session.
  • Possibly a list of suggestions to the legislature for the 2011 Session.
As opposed to accomplishing:
  • Research and documentation of how other states' (& countries') long-term strategies are already producing significant tech-based economic development outcomes
  • An outlined roadmap for the creation of a significant entity representative of the S&T community, policy makers and the academic sector to develop a tech-based economic development strategy for Minnesota (so no one single force can be "blamed" for not getting things done, and finally, everyone who has a stake in the outcome will have a role in establishing & delivering outcomes)
  • A game plan to get the entity established early in the 2010 Session, charged with measurable deliverables, so it can be up and running no later than May, 2010
  • Minnesota starts creating an Eco System to support tech-based economic development, linking current assetts with a quality backdrop for evaluating future ideas so we can make Priority Lists and start checking things off The List
The fun thing about predictions is they can be hilariously, or fortuitously, incorrect. For the sake of Minnesota's science & technology future ability to compete, let's hope this prediction is 100% WRONG. 
 
* Bio Business Alliance of Minnesota (BBAM Destination 2025) & MN Nano reports on Economic Impact Analysis (EIA)
To receive a copy of the MN Nano EIA, contact Lynne Osterman
(Note: technically, neither report will characterize the 10-year timeframe outcomes using the same verbage as noted above)
** HF2088, Sect. 16 (42.29-43.22)
 

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An Amazing History but the Hard Disk Drive Industry is Just Getting Warmed Up

By Ed Gage, Eric Hockert

The magnetic hard disc drive (HDD) industry has been amazing in its ability to increase drive capacity and performance during its history. For example, bit storage density has gone from the 5 kilobits per square inch of the original IBM Ramac drive to currently approaching 500 Gbits per square inch in upcoming products. This increase of 10 million times has been accomplished by 50 years of continuously scaling down the critical dimensions of the recording system and incorporating new technologies. Nanotechnology has played a key role. Examples include: the media recording layer designed to self order in a granular structure with grain sizes on the order of 10 nm in diameter, the critical dimensions of the magnetic writer which are on the order of 10 nm, and the recording head maintained at a distance of a couple of nanometers above the spinning disk by using a high pressure air bearing and a thermo-mechanical actuator. 

As HDD technology approaches areal densities of 1Tbit per square inch, we need to further reduce the grain area in the media in order to maintain enough grains per bit which is critical for a good signal to noise ratio. As we reduce the grain size, its magnetic energy is reduced and the magnetic orientation which stores the information becomes susceptible to thermal fluctuations. One solution is to increase the magnetic energy density of the media material. This leads to difficulties in producing a magnetic field from the recording head that has sufficient strength to produce a high quality magnetic pattern in the media. It is estimated that this superparamagnetic effect will limit areal densities of today's recording system to about 1Tbit per square inch.

One solution to superparamagnetic effects is to use high anisotropy materials such as FePt and heat them up during the recording process to lower their coercivity to the point it can be written with available head fields. This approach is called Heat Assisted Magnetic Recording, HAMR [1]. As we heat the media to near the Curie temperature, we want to avoid heating neighboring tracks to prevent increased thermal fluctuations and erasure. The track pitch at 1 Tbit per square inch is about 60 nm. How can we produce a small well confined hot spot on the track to be recorded? Optical data storage uses a highly focused laser to create thermal spots on the order of 200 nm or larger. This spot size is too large to limit the heat to the desired track pitch.

 
near field transducer_HAMR head 
Figure 1. A top down view of the gold lollipop near field transducer is shown in a) and an air bearing surface (ABS) view (b) of the integrated HAMR head shows the magnetic pole, peg of the near field transducer, and the optical waveguide core.
 
At Seagate, we have developed a plasmonic antenna device and integrated it into our recording heads [2]. These plasmonic devices are excited by a tightly focused laser beam from a planar solid immersion mirror integrated into a magnetic recording head. The "lollipop" near field transducer (NFT) is shown in figure 1. It consists of a gold disk whose dimensions are chosen to yield a plasmonic resonance at 830 nm. The peg serves to couple to and confine the field in the recording media. When integrated with the high anisotropy media with the correct thermal properties, we have shown that it is possible to confine the heat and record magnetic tracks on the order of 50 nm wide as shown in figure 2.

The hard disk drive industry has an impressive history of incorporating new technologies such as giant magneto-resistive sensors and nanometer resolution thermal actuators to continue to increase capacity and performance of data storage. Heat Assisted Magnetic Recording is being developed to allow another order of magnitude increase in areal density.

50 nm recorded track width
Figure 2.  a) A magnetic force microscope image shows a recorded HAMR track on a high anisotropy FePt disk.  In b) the signal amplitude is plotted versus cross track position from a scan of the reader across the recorded track showing the ~ 50 nm recorded track width.

References:

[1] M. H. Kryder et. Al, Proceedings of the IEEE, 96, 1810-1835 (2008)
[2] W. Challener et. al. Nature Photonics 3, 220 - 224 (2009)


 
Handling Ownership Issues For A Mutually Satisfying Collaboration

By Benjamin Tramm

Nanotechnology, by its very nature, typically requires expensive and highly specialized machinery. For this reason, many early stage companies must look to collaboration with others in order to get off the ground. Such collaboration can provide access to lab space, for example, and may also provide access to other resources, such as the specialized knowledge of others from diverse technological backgrounds.

Collaboration does not come without its risks, and savvy companies will consider these risks carefully before engaging in a collaborative effort. One of the considerations that must be carefully thought out is how to handle any intellectual property that may be developed through the collaboration.

Absent an agreement to the contrary, the default ownership model in the United States is that an inventor or author owns the complete rights to intellectual property associated with his or her creation. When multiple people collaboratively invent or author, each is granted an equal and undivided interest in the creation. This model can lead to problems down the road. Say, for example, that one inventor at company A begins to commercialize a patented technology. The other inventor at company B could then turn around and sell his or her interest in the invention to company A's biggest competitor, giving the competitor an equal and undivided interest in the patented technology.

The parties can, however, contract out of this default model to define their own model for intellectual property ownership. In order to develop a mutually beneficial arrangement, it is usually necessary for the parties to engage in an open discussion about each party's interests.  Assignments or licenses can be used to define an ownership model that is mutually satisfying. The result should be a written collaboration (or "co-development") agreement that specifies the agreement of the parties in clear and unambiguous terms.

If patents or trade secrets are desired for any of the technology being developed, it is important to have a written non-disclosure agreement in place. As its name implies, a trade secret will be required to be kept in secret. If patents are to be applied for, it is important to be sure that the technology remains confidential until the necessary patent applications are filed. Most countries outside of the United States require absolute novelty, which typically means that a public disclosure of the invention could result in a loss of some or all of the intellectual property rights. A non-disclosure agreement is useful to ensure that the sharing of information between companies is not considered a public disclosure.

A well developed collaboration agreement can be a catalyst to collaboration, by defining the framework for the collaboration. Knowing that the intellectual property issues have been resolved up front, the parties can be free to engage in a mutual exchange of ideas. 


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In This Issue
--AFM Nano Torsion Probes
--MN Nano 2009 Legislation
--Seagate Hard Disk
--Ownership Issues in Collaboration
Enewsletter Work Group

shweta
Shweta Sharma
(MN Nano ENewsletter Chair)
Sr. MEMS Engineer
Goodrich Corporation 
 
ben
Benjamin Tramm
Intellectual Property Attorney
Merchant & Gould

eric
Eric Hockert
Technology Marketing Manager
University of Minnesota

Marianne
Marianne Timm
Intellectual Property Attorney
Merchant & Gould

matt
Matthew Hollister
Technical Advisor 
Merchant & Gould

Amanda
Amanda Barthel
MN Nano Account Executive
 
 

Upcoming Events

Seminars at the Center for Nanostructure Applications

Check out the CNA calendar for upcoming seminar topics and dates.
University of Minnesota

2009 IEST Fall Conference
Nov 9-12
Illinois, USA

NanoEurope 2009
Nov 25-26
Switzerland



MN Nano Membership Briefing
December 2, 2009
St. Paul College
Join MN Nano members and the State Science & Technology Committee to discuss statewide collaboration opportunities, the legislative agenda for this session, for an update on the potential  Nano Commercialization Center and a tour of the new clean room the College debuted this past year.  Registration and continental breakfast at 7:30 a.m., program at 8, concluding with tour at 10.  This event is $10 for MN Nano members and $20 for non-members.  Parking is FREE for all attendees.  To register, call 763.245.3902 or email
Lynne Osterman


MN Nano Nano/MEMS Sensors
Special Interest Group
The objective of the Nano/MEMS sensor special interest work group (SIG) is to build a forum to foster collaborative research and to enhance the prospects of improved private sector and university research.
If you have suggestions for speaker topics, speakers for the upcoming SIG event (early 2010) or want to get more involved in the Sensors SIG, please
contact Dadi Setiadi


MN Nano Student Chapter
Interested in reaching the engineers, researchers and technicians you need to keep your company moving forward? MN Nano is starting a Student Chapter and is looking for a Host Company to sponsor student membership fees. The sponsoring company will receive promotional credit on MN Nano's web site. For more information on how your company can become a 2010 Student Chapter Sponsor, please contact Lynne Osterman



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