Sonotrode
Encyclopedia
The sonotrode is a piece of metal or tool that is exposed to ultrasonic
vibration, and then gives this vibratory energy in an element to apply (gas
, liquid
, solid
or tissue
).
Following a standard frequency
range of ultrasonic use (from 20 kHz to 70 kHz), the sonotrode resonates in frequency as "contraction" and "expansion" x times per second (x is the frequency). The amplitude
is about 13 to 130 micrometres.
This resonance
of acoustics wave
of a half-wavelength, follows the characteristics of modulus elasticity of the material E (Young's modulus
), its density
ρ, the speed of sound
through this material c, and the frequency f.
The shape of the sonotrode (round, square, with teeth, profiled ...), depends on the quantity of vibratory energy
and a physical constraint for a specific application.
Its geometry must be optimized following the shape
of the application.
They are made of titanium, aluminum or steel, with or without heat treatment
(carbide
)
Sonotrodes of small diameter are sometimes called probes.
For an ultrasonic welding or cutting application, the sonotrode gives energy directly to the welding contact area, with little diffraction
. This is particularly helpful when vibrations (wave propagation
) could damage surrounding electronic components.
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
vibration, and then gives this vibratory energy in an element to apply (gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
, liquid
Liquid
Liquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
, solid
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...
or tissue
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
).
Following a standard frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
range of ultrasonic use (from 20 kHz to 70 kHz), the sonotrode resonates in frequency as "contraction" and "expansion" x times per second (x is the frequency). The amplitude
Amplitude
Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...
is about 13 to 130 micrometres.
This resonance
Resonance
In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
of acoustics wave
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
of a half-wavelength, follows the characteristics of modulus elasticity of the material E (Young's modulus
Young's modulus
Young's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. In solid mechanics, the slope of the stress-strain...
), its density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
ρ, the speed of sound
Speed of sound
The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....
through this material c, and the frequency f.
The shape of the sonotrode (round, square, with teeth, profiled ...), depends on the quantity of vibratory energy
Vibration
Vibration refers to mechanical oscillations about an equilibrium point. The oscillations may be periodic such as the motion of a pendulum or random such as the movement of a tire on a gravel road.Vibration is occasionally "desirable"...
and a physical constraint for a specific application.
Its geometry must be optimized following the shape
Shape
The shape of an object located in some space is a geometrical description of the part of that space occupied by the object, as determined by its external boundary – abstracting from location and orientation in space, size, and other properties such as colour, content, and material...
of the application.
They are made of titanium, aluminum or steel, with or without heat treatment
Heat treatment
Heat treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass...
(carbide
Carbide
In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding type as follows: salt-like, covalent compounds, interstitial compounds, and "intermediate" transition metal carbides...
)
Sonotrodes of small diameter are sometimes called probes.
For an ultrasonic welding or cutting application, the sonotrode gives energy directly to the welding contact area, with little diffraction
Diffraction
Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...
. This is particularly helpful when vibrations (wave propagation
Wave propagation
Wave propagation is any of the ways in which waves travel.With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves....
) could damage surrounding electronic components.