Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Experimental Results on Contact Area Measurements

In course

ME-412: Experimental methods in engineering mechanics

This course gives an advanced treatment of experimental methods in the context of mechanics by way of example. Students will construct significant components of experimental apparatus, use their apparatus to collect data, interpret the resulting data, and ...

Description

This lecture presents the experimental results obtained by Hugo, Antoine, and David on measuring the real area of contact. They discuss the methodology used, including the computation of resistance, conductance, and surface contact. The comparison with Tabor theory and the importance of cleanliness in measurements are also highlighted.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

John Martin Kolinski

Dr. Kolinski studied Applied Mathematics (Sc.M.) and Applied Physics (Ph.D.) at Harvard University, completing a PhD under the supervision of L. Mahadevan and Shmuel Rubinstein on the role of air in droplet impact. John did his post-doc at the Hebrew University of Jerusalem in Israel supported by the Fulbright post-doctoral fellowship. At HUJI, he worked on interfacial instabilities in soft matter in the labs of Eran Sharon and Jay Fineberg. John continues his research into interfacial mechanics at EPFL in EMSI, his newly founded laboratory for the study of Engineering Mechanics of Soft Interfaces.

Official source

Related concepts (4)

Contact resistance

The term contact resistance refers to the contribution to the total resistance of a system which can be attributed to the contacting interfaces of electrical leads and connections as opposed to the intrinsic resistance. This effect is described by the term electrical contact resistance (ECR) and arises as the result of the limited areas of true contact at an interface and the presence of resistive surface films or oxide layers. ECR may vary with time, most often decreasing, in a process known as resistance creep.

Electrical resistance and conductance

The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ℧). The resistance of an object depends in large part on the material it is made of.

French Resistance

The French Resistance (La Résistance) was a collection of organizations that fought the Nazi occupation of France and the collaborationist Vichy régime in France during the Second World War. Resistance cells were small groups of armed men and women (called the Maquis in rural areas) who conducted guerrilla warfare and published underground newspapers. They also provided first-hand intelligence information, and escape networks that helped Allied soldiers and airmen trapped behind Axis enemy lines.

Resistance movement

A resistance movement is an organized group of people that tries to resist the government or an occupying power, causing disruption and unrest in civil order and stability. Such a movement may seek to achieve its goals through either the use of nonviolent resistance (sometimes called civil resistance), or the use of force, whether armed or unarmed. In many cases, as for example in the United States during the American Revolution, or in Norway in the Second World War, a resistance movement may employ both violent and non-violent methods, usually operating under different organizations and acting in different phases or geographical areas within a country.

Related lectures (19)

Contact Resistance in Semiconductor Devices

Explores contact resistance in semiconductor devices and methods to measure and extract it.

Electromechanical Conversion MOOC: Electromechanical conversion I

Explores electromechanical force conversion and energy balance in electromechanical systems.

Sinusoidal Quantities: Analytical Expressions and Parameters MOOC: Electrical engineering I

Covers the analytical expressions and parameter definitions of sinusoidal quantities in electrical engineering.

Untitled

Ideal Sources of emf in Circuits

Discusses ideal sources of emf in circuits and Kirchoff's rules for circuit analysis.

Related concepts (4)

Contact resistance

Electrical resistance and conductance

French Resistance

Resistance movement