Navigation Links
'Heftier' atoms reduce friction at the nanoscale, study led by Penn researcher reveals
Date:11/1/2007

PHILADELPHIA - A research team led by a University of Pennsylvania mechanical engineer has discovered that friction between two sliding bodies can be reduced at the molecular, or nanoscale, level by changing the mass of the atoms at the surface. Heavier atoms vibrate at a lower frequency, reducing energy lost during sliding.

The study appears in the November issue of the journal Science.

Penn researchers, along with colleagues at the University of Houston and the University of Wisconsin now at IBMs Zurich Research Laboratory and the Argonne National Laboratory, used atomic force microscopy like an old-fashioned record needle, sliding it along single-crystal diamond and silicon surfaces to measure the force of friction. Before doing so, researchers coated each crystal surface with one of two adsorbates designed to best exhibit variations in the mass of the atoms at the surface without changing the chemistry. The first adsorbate was a single layer of hydrogen atoms. The second was its chemically similar but heavier cousin, deuterium, a hydrogen atom with a neutron stuffed inside its nucleus.

Our study found that the larger mass of the terminating atoms at the surface, in this case deuterium, led to less energy lost to heat in the system, Robert Carpick, associate professor of mechanical engineering and applied mechanics at Penn, said. The larger atomic mass of deuterium results in a lower natural vibration frequency of the atoms. These atoms collide less frequently with the tip sliding over it, and thus energy is more slowly dissipated away from the contact.

The single layer of atoms at the surface of each crystal acts as an energy transfer medium, absorbing kinetic energy from the tip of the atomic force microscope. The tips were less than 50nm in radius at their ends. How much energy is absorbed is dependent, researchers found, on the adsorbates natural atomic vibration frequencies. The heavier an atom, the lower its vibrational freque
'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert

Page: 1 2

Related biology news :

1. Male circumcision reduces risk of HIV transmission from women to men
2. Deficiency of growth hormone and IGF-1 reduces cancer and kidney disease, but creates other problems
3. Use of PET can reduce, may eliminate more strenuous drug development trials with animals
4. Solutions that reduce death of marine life reeled in by International Smart Gear Competition
5. Physiological effects of reduced gravity on bacteria
6. New strategies to reduce hospital-aquired infections
7. New miniaturised chip dramatically reduces time taken for DNA analysis
8. Scalpel-free surgery could reduce risk of HIV and hepatitis exposure for health care workers
9. Newly recognized gene mutation may reduce seeds, resurrect plants
10. New processing method reduces peanut allergenicity
11. Blocking the nerve receptor EP1 in mouse models reduces brain damage caused by stroke
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/10/2014)... June 30, 2014  Aware, Inc. (NASDAQ: ... services, previously announced on June 26, 2014 that its ... of $1.75 per share, or approximately $40 million in ... 10, 2014 and a payment date of July 24, ... it had set an ex-dividend date for this special ...
(Date:7/10/2014)... COMMACK, N.Y. , July 2, 2014 ... Inc. (ABD) to announce the appointment of the world-renowned ... its Board of Directors. Dr. Ginsburg, with ... two facilities: NY Presbyterian Hospital and Good Samaritan Regional ... Breathing Pacemaker since the late 1980,s and is considered ...
(Date:7/10/2014)... , July 3, 2014 Research ... addition of the "Global Gesture Recognition & ... - Forecasts to 2020" report to their ... Global Gesture Recognition & Touch-Less Sensing Market ... around for a while, but the companies were ...
Breaking Biology News(10 mins):NASDAQ Sets Ex-Dividend Date for Aware, Inc.'s Special Cash Dividend of $1.75 Per Share 2Avery Biomedical Devices, Inc. announces the appointment of Mark E Ginsburg, M.D. to its Board of Directors 2Global Gesture Recognition & Touch-Less Sensing (2D, 3D, Ultrasonic, IR, Capacitive) Market - Forecasts to 2020 2
... mammoths and ancient American horses may have been grazing ... than previously thought. After plucking ancient DNA from frozen ... cutting-edge techniques to uncover "genetic fossils" of both species ... 10,500 calendar years. This new evidence suggests that at ...
... look forward to ultra-low powered or self powered electronic ... is made possible with power management and cutting-edge energy ... and higher energy efficiency in electronic devices and systems. ... for power management and energy harvesting. To pre-position the ...
... part of an international team that has used DNA samples ... of North America,s woolly mammoths and ancient horses. The ... Duane Froese and his colleagues counters an important extinction theory, ... concluded that more than half of the large mammals in ...
Cached Biology News:Late-surviving megafauna exposed by ancient DNA in frozen soil 2Late-surviving megafauna exposed by ancient DNA in frozen soil 3Late-surviving megafauna exposed by ancient DNA in frozen soil 4NTU and EDB launch S$50 million ($36 million) integrated circuit design research center 2NTU and EDB launch S$50 million ($36 million) integrated circuit design research center 3
(Date:7/10/2014)... EvoDerma ’s NOOME Anti-Aging Motion has been upgraded for ... a second treatment cup to help prevent and smooth skin ... thinner on the edges for a softer contact with the ... surfaces on the face, neck and décolleté. Choose to use ... such as the cheeks and neck, or opt for the ...
(Date:7/10/2014)... 10, 2014  Kainos Capital, a firm specializing in ... that it has acquired the Slim-Fast brand from Unilever. ... Terms of the transaction were not disclosed. ... business that markets ready-to-drink shakes, powders, bars and snacks ... and in the United Kingdom ...
(Date:7/10/2014)... 2014 -- According to the International Atomic Energy ... comes from terrorists acquiring sufficient quantities of plutonium ... crude nuclear explosive device. The IAEA also notes ... involved gram-level quantities, which can be challenging to ... a new study appearing this week in the ...
(Date:7/10/2014)... extremely challenging because there are many genetic variants that ... Now investigators reporting in the July 3rd issue of ... describe a strategy that may help reveal how such ... environmental exposures to affect the development of the nervous ... predispose individuals to schizophrenia. , The work takes ...
Breaking Biology Technology:Introducing a New Bonus Treatment Cup for EvoDerma’s NOOME Anti-Aging Motion 2Kainos Capital Acquires Slim-Fast From Unilever 2Sensitive detection method may help impede illicit nuclear trafficking 2New strategy could uncover genes at the root of psychiatric illnesses 2
... HER3 Total Protein ... Assays in Collaborative Biomarker Study, SOUTH SAN FRANCISCO, ... ) today announced that scientific,collaborators have presented additional clinical ... means to measure HER2 total,protein and homodimer levels and ...
... Medline Industries, Inc., the,nation,s largest privately held manufacturer ... has signed a three-year agreement to,purchase mouth rinse ... personal care, infection control and diagnostic use in ... in the healthcare market, we are,happy to extend ...
... The 21st Century Health Care Forum discusses the future of Continuing ... ... FRANCISCO, June 2 Accredited online nursing courses,are replacing traditional classroom-based ... flexibility in,their credentialing options., Ann Johnson, CEO of Wild Iris ...
Cached Biology Technology:Monogram Announces Presentation of Clinical Data for the HERmark(TM) Breast Cancer Assay at the 44th ASCO Annual Meeting 2Monogram Announces Presentation of Clinical Data for the HERmark(TM) Breast Cancer Assay at the 44th ASCO Annual Meeting 3Monogram Announces Presentation of Clinical Data for the HERmark(TM) Breast Cancer Assay at the 44th ASCO Annual Meeting 4Monogram Announces Presentation of Clinical Data for the HERmark(TM) Breast Cancer Assay at the 44th ASCO Annual Meeting 5Monogram Announces Presentation of Clinical Data for the HERmark(TM) Breast Cancer Assay at the 44th ASCO Annual Meeting 6Medline Signs 3-Year Purchasing Agreement for Mouth Rinse From Chester Labs 2Modernizing Continuing Education With Online Courses 2
Amyloid stain....
...
Human sIL-2R/CD25 ELI-PAIR Kit...
STX18 Immunogen: STX18 (NP_058626, 101 a.a. ~ 200 a.a) partial recombinant protein with GST tag. Storage: -20 C, Avoid Freeze/Thaw Cycles *Available for distribution in the US only...
Biology Products: