Related Experiment Video
Updated: Jun 6, 2026
13:29
Electric and Magnetic Field Devices for Stimulation of Biological Tissues
Published on: May 15, 2021
Electric-field induced strain in biological tissues
1Department of Physics, Ryerson University, Toronto, Ontario M5B2K3, Canada. odoganay@ryerson.ca
The Journal of the Acoustical Society of America
|November 30, 2010
Summary
A novel electrical field effect induces mechanical strain in biological tissues. This electrokinetic phenomenon, observed at physiological levels, expands tissues perpendicularly to the electric field, offering new insights into tissue mechanics.
Area of Science:
- Biophysics
- Materials Science
- Biomedical Engineering
Background:
- Existing models like piezoelectricity, electrostriction, and thermal effects do not explain observed tissue strain.
- Physiological-level direct-current electrical fields are commonly used in various biomedical applications.
Purpose of the Study:
- To report and characterize a newly observed effect of electrical fields on biological tissues.
- To investigate the mechanism behind electrically induced mechanical strain in tissues.
Main Methods:
- Applied a physiological-level direct-current electrical field (1.4 V/cm) to biological tissues and gel phantoms.
- Analyzed induced mechanical strain by processing ultrasound echo signals.
- Measured tissue expansion perpendicular to the applied electric field.
Main Results:
- A time-varying mechanical strain was induced in various biological tissues and gel phantoms by a direct-current electrical field.
- The induced strain, characterized by perpendicular expansion, was not attributable to known effects like piezoelectricity or electrostriction.
- The expansion rate demonstrated dependence on the history of the applied electric field, with minimal changes in the speed of sound.
Conclusions:
- A new electrokinetic effect is proposed to explain the observed electrically induced mechanical strain in biological tissues.
- This finding may have implications for understanding tissue behavior under electrical stimulation and for developing new biomedical technologies.
More Related Videos
Related Concept Videos
01:23Induced Electric Fields
The fact that emfs are induced in circuits implies that work is being done on the conduction electrons in the wires. What can possibly be the source of this work? We know that it’s neither a battery nor a magnetic field, as a battery does not have to be present in a circuit where current is induced, and magnetic fields never do any work on moving charges. The source of the work is in fact an electric field that is induced in the wires. For example, if a stationary conductor is placed in a...
01:13Strain Energy
Strain energy is a fundamental concept in the field of materials science and structural engineering, describing the energy absorbed by a material or structure when it is deformed under load.
Consider a rod that is fixed at one end and subjected to an axial force at the free end. This axial force induces stress within the rod, leading to its elongation. As the axial force increases, so does the elongation of the rod, illustrating a direct relationship between the force applied and the resulting...
Consider a rod that is fixed at one end and subjected to an axial force at the free end. This axial force induces stress within the rod, leading to its elongation. As the axial force increases, so does the elongation of the rod, illustrating a direct relationship between the force applied and the resulting...
01:20Strain-Energy Density
Understanding the strain energy density in materials under axial load is crucial for evaluating their mechanical behavior and durability. When a rod is subjected to such a load, it elongates and stores energy, known as strain energy, as potential energy within the material. This energy is measured in terms of energy per unit volume.
In the elastic region of a material, the relationship between the stress and the strain is linear and follows Hooke's Law. The strain energy density in this region...
In the elastic region of a material, the relationship between the stress and the strain is linear and follows Hooke's Law. The strain energy density in this region...
01:22Elastic Strain Energy for Normal Stresses
Strain energy quantifies the energy stored within a material due to deformation under loading conditions, a fundamental concept in materials science and engineering. The strain energy can be modeled when a material is subjected to axial loading with uniformly distributed stress. In this scenario, the stress experienced by the material is the internal force divided by the cross-sectional area, and the strain induced is directly proportional to this stress through the modulus of elasticity.
If...
If...
01:19Thermal Strain
Thermal strain is a concept that arises when we consider how temperature changes affect structures. Unlike the conventional assumption that structures remain constant under load, real-world scenarios often involve temperature fluctuations that can significantly impact these structures. Consider a homogeneous rod with a uniform cross-section resting freely on a flat horizontal surface. If the rod's temperature increases, the rod elongates. This elongation is proportional to the temperature...
01:27Induced Electric Fields: Applications
An important distinction exists between the electric field induced by a changing magnetic field and the electrostatic field produced by a fixed charge distribution. Specifically, the induced electric field is nonconservative because it does not work in moving a charge over a closed path. In contrast, the electrostatic field is conservative and does no net work over a closed path. Hence, electric potential can be associated with the electrostatic field but not the induced field. The following...