Michael Nosonovsky - Assistant Professor
3200 North Cramer Street
Milwaukee, WI 53211
P.O. Box 784
Department of Mechanical Engineering
University of Wisconsin-Milwaukee
Milwaukee, WI 53201
Total citations: 3176 (one of the most cited scientists in the World in the rank of Assistant Professor of Mechanical Engineering)
Funded Projects ($1.07M) External funds (Total $509K)
Internal funds (Total $680.9k)
In the Media
"Although superhydrophobic surfaces repel water, do they keep off ice
as well? Not always. As Michael Nosonovsky and Vahid Hejazi at the University
of Wisconsin-Milwaukee explain, the often-bumpy of superhydrophobic surfaces
traps air pockets between the solid and the liquid. When water freezes,
these air pockets become the basis of cracks in the ice, and the larger
cracks are, the easier it is to dislodge ice off a surface." (Charles Q.
Choi "Worth Pitching?: Mysteries of Rain and Ice" Scientific American blog,
October 5, 2012)
"In 2007, Nosonovsky showed that if you got the architecture of a surface\92s roughness just right, creating caves, nooks and crannies that bend back in on themselves, you could create repulsive surface forces equating to huge contact angles for all sorts of liquids. It was a simple but game-changing insight. " (Jessica Griggs, "Omniphobia: the stuffs that stick at nothing" New Scientist on 24 November 2012, p 46-49)
"The new findings are an important step towards creating robust omniphobic surfaces, says Michael Nosonovsky. Omniphobic surfaces repel contaminants in an environmentally friendly way, he notes, so they could be used, for instance, as a coating for self-cleaning solar panels." (Sid Perkins "Blueprint to repel oil and water" Science News, December 6, 2008)
"In 2007, Nosonovsky created a theoretical surface architecture
that addressed superhydrophobicity at both nano- and microscales, with crannies
that bent back in on themselves. It was used by scientists at the Massachusetts
Institute of Technology to make ketchup bottles that allowed the product
to slide out without sticking to the sides" ("Super-surfaces suggested
by nature" By Laura L. Hunt, UWM News, August 23, 2013)
What colleagues say
"Dr Nosonovsky is a highly successful, productive and original scholar with an impressive publication record. He performs outstanding cutting-edge research in various areas of mechanics of materials related to surface science and tribology" (CEAS Excellence in Research Award).
"You are extremely productive as always hitting top journals. I take pride as you started with me when you were a young scientist and I have seen you grow." (Prof. Bharat Bhushan, Ohio State University)
"Michael, This is great that you have been able to publish about self-healing, self-lubricating and self-cleaning materials in Nature. This will certainly advance our efforts in this area" (Prof. Pradeep K. Rohatgi, UWM)
"This is very impressive! Keep up your quality of work." (Prof. Ryoichi S. Amano, UWM)
What alumni say
"I was doing well in my classes, but nothing really caught my attention until I took Professor Nosonovsky's class on biomimetic and functional surfaces, I just immediately loved it.... When I compared what I was doing in Professor Nosonovsky's lab with my options in traditional engineering, I decided my money was on the freshwater applications. Especially after my research paper was published, I knew this was the field I wanted to continue in." (Tyler Hurd, engineer at Pentair, Glendale, WI)
"Dr. Nosonovsky is a great and very patient and one of the best instructors I have had at UWM... I especially liked taking Mechanical Vibrations with him as he taught the a completely different approach to solving vibration problems that we were not familiar with from our undergraduate engineering classes" (Ohganetega Anene-Maidoh, graduate student at Georgia Tech)
M. Nosonovsky & V. Mortazavi. Friction-Induced Vibrations and Self-Organization: Mechanics and Non-Equilibrium Thermodynamics of Sliding Contact (CRC Press/Taylor & Francis, 2013)
Friction is usually thought as a process that leads to irreversible dissipation of energy and wear is thought of as irreversible deterioration. Many scientists and engineers do not realize that under certain conditions friction can lead to the formation of new structures at the interface, including in-situ tribofilms, and various patterns at the interface. Friction-induced self-organization was studied mostly by scholars in Eastern Europe in the 1970-1990s although the field remains exotic to many tribologists in other countries.
Friction-induced instabilities are related to friction-induced self-organization. Friction is usually thought as a stabilizing factor; however, sometimes friction leads to the instability of sliding, in particular when friction is coupled with another process. For example, thermoelastic instabilities were studied extensively by J. R. Barber. These instabilities arise from the fact that friction is coupled with heat generation, which, in turn, is coupled with material expansion, creating a positive feedback. If friction increases locally due to a random fluctuation, more heat is generated, leading to higher local normal pressures at the interface and, in turn, to increased friction. Thus a random fluctuation has a tendency to grow, signifying the instability. A similar situation occurs when the coefficient of friction decreases with the increasing sliding velocity: a small random increase of the sliding velocity leads to a decrease of the frictional resistance and to the further increasing of velocity. It was discovered in the 1990s that frictional elastodynamic instabilities (the Adams-Martins instabilities) occur even in the case when the coefficient of friction is constant. Instabilities are related to self-organization because they constitute the main mechanism for pattern formation. At first, a stationary structure loses its stability; after that, vibrations with increasing amplitude occur, leading to a limiting cycle corresponding to a periodic pattern.
We discuss a general variational stability criterion of the stationary state of frictional sliding, δ^2(dS/dt)>0, where dS/dt is the rate of entropy production and δ^2 is the second variation. The criterion is very powerful since it allows combining very diverse mechanisms of frictional instabilities within one general theory. The entropy S can include pure mechanical, thermodynamic, heat and mass transfer, chemical reactions, and other terms. Variations of the relevant parameters (physically corresponding to small random fluctuation) can either be suppressed or expand. The stability criterion captures this trend. For the case of the constant temperature T, sliding velocity V, and normal load W, the criterion can be significantly simplified.
Furthermore, we wanted to combine the mechanical and thermodynamic methods in tribology. From the thermodynamic point of view, friction and wear are two sides of the same phenomenon: irreversible energy dissipation and material deterioration during sliding. As with any irreversibility, both friction and wear are the consequences of the second law of thermodynamics. It would be therefore logical to expect that the laws of friction and wear (such as the Coulomb and Archard laws) are deduced from the thermodynamic principles of irreversibility. However, in practice this is difficult to achieve. We suggest a procedure on how this can be done using Onsager\92s linearized laws of irreversible thermodynamics combined with the asymptotic transition from the bulk to the interface. Non-equilibrium (irreversible) thermodynamics is also useful for the study of friction-induced self-organization. In general, the place of thermodynamic methods in tribology is growing.
The area of friction-induced self-organization is related to novel biomimetic materials, such as self-lubricating, self-cleaning, and self-healing materials. These "smart " materials have the embedded capacity for self-organization, leading to their unusual properties. Understanding the structure-property relationships leading to self-organization is the key to designing these novel materials. It is noted that these materials often have hierarchical organization, which makes them similar to biological materials.
All this background information caused us to look at friction, as a physical phenomenon, from a different angle. For most conventional textbooks on mechanics, Coulomb\92s dry friction is quite an external phenomenon, which is postulated in the form of laws of friction (usually, the Coulomb-Amontons laws) introduced in an arbitrary and ad hoc manner in addition to the constitutive laws of mechanics. Furthermore, the very compatibility of the Coulomb friction laws with the laws of mechanics is questionable due to the existence of the so-called frictional paradoxes or logical contradictions in the mechanical problems with friction. The Coulomb-Amontons law is not considered a fundamental law of nature, but an approximate empirical rule, whereas friction is perceived as a collective name for various unrelated effects of different nature and mechanisms, such as adhesion, fracture, and deformation, lacking any internal unity or universality.
Despite this artificial character of friction laws in mechanics, Coulomb friction is a fundamental and universal phenomenon that is observed for all classes of materials and for loads ranging from nanonewtons in nanotribology to millions of tons in seismology. There is a clear contradiction between the generality and universality of friction and the artificial manner of how the friction laws are postulated in mechanics and physics. Is it by chance that all these diverse conditions and mechanisms lead to the same (or at least similar) laws of friction? If a thermodynamic approach is used consistently, the laws of friction and wear can be introduced in a much more consistent way.
These reflections about the fundamental nature of friction and its status in physics caused us also to examine with great attention the role of friction in physics throughout the history of science. In the days of Aristotle\92s "Physics, " friction was seen as a fundamental force having the same status as inertia force (nothing would move without inertia, nothing would stop without friction). The problem of inertia force was one of the central issues of physics throughout the middle ages, until it was finally resolved by Galileo, leading to the foundation of modern mechanics by Newton in the late 17th century. In contrast, friction force was not usually seen as a fundamental force of nature and became somewhat marginal in modern mechanics. Viewing friction as a fundamental force of nature to some extent restores the original Aristotelian approach.
One prominent manifestation of the surface forces is the Lotus effect. The ancient Hindu poem Bhagavad Gita says about the seeker of truth "Having abandoned attachment, he acts untainted by evil, just as a lotus leaf is not wetted." Lotus leaf emerges clean from dirty water due to special hierarchical microstructure of its surface, and scientists mimic superhydrophobic and self-cleaning properties of the lotus effect. Furthermore, surfaces that repel various substances, from oil to bacteria, to ice are being developed by scientists.
Besides wetting, hydrophobicity is crucial for many important effects, such as the "hydrophobic effect" and hydrophobic interactions. For two hydrophobic molecules (e.g., hydrocarbons) placed in water, there is an effective repulsive hydrophobic force due to their interaction with the water medium. The hydrophobic effect, entropic in its nature, is responsible for folding of proteins and other macro-molecules and has wide application in many physical, biological, and chemical processes. We are investigating the similarities between the superhydrophobicity, icephobicity and adhesion on various levels, from the thermodynamic entropic nature of these interaction, to the parallelism between snowflake formation, protein folding and frictional stick-slip, to engineering applications such as superhydrophobic nanoengineered concretes and self-cleaning materials for water industry.
There are many interesting effects in how biological materials and tissues are organized (e.g., their multiscale hierarchical organization) which are now well understood by biologists and the knowledge should be transferred into engineering. In the past, we suggested that thermodynamic methods of analysis of self-organized patterns and structures can be applied to the materials with embedded self-healing mechanisms. Such methods will allow to relate the structure (including the micro- and nanostructure) of such materials and composites to their self-healing properties. The structure-property relationships help designing the optimized structure and serve as a guidance for synthesizing such materials, for which currently the trial-and-error approach is usually employed.