Related Experiment Video
Updated: Jun 22, 2026

Atomic Force Microscopy to Study the Physical Properties of Epidermal Cells of Live Arabidopsis Roots
Published on: March 31, 2022
Area and edge effects in radiometric forces
N Selden1, C Ngalande, S Gimelshein
1University of Southern California, Los Angeles, California 90089, USA.
Abstract:
The radiometric force on several configurations of heated plates placed in a stagnant gas is examined experimentally, with a high-resolution thrust stand, and numerically using the direct simulation Monte Carlo method and a discrete ordinate solution of a model kinetic equation. A wide range of pressures from 0.006 to 6 Pa was examined, corresponding to Knudsen numbers from 20 to 0.02, in argon and helium test gases. The radiometric force, important in a number of emerging micro- and nanoscale applications, is shown to be mostly area dependent in the transitional regime where it reaches its maximum at Kn approximately 0.1.
Related Concept Videos
Biological Effects of Radiation
Types of Forces
Variation in Acceleration due to Gravity near the Earth's Surface
The difference between the true and apparent weights is proportional to the square of the Earth's angular speed. Since the...
Tidal Forces
Energy Diagrams - II
The point in the energy diagram at which the system’s potential energy is the lowest is known as the local minima. The system tends to stay in this position indefinitely unless acted upon by a net force. The slope of the potential energy diagram at the local minima is zero, indicating that zero net force is acting on the system. The slope...
Radiation Pressure: Problem Solving
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...

