Key Components of and Accessories for Ultrasonic Probe Sonicators

The adoption of ultrasonic cleaning and processing systems has gained momentum especially in the medical, pharmaceutical, and industrial sectors. At the heart of these systems are ultrasonic probe sonicators which mainly comprise three key components: an ultrasonic generator, a converter and a probe. Among other applications, such sonicators are commonly applied for creating emulsions, nanoparticle dispersion, cell lysis and homogenization.

The ultrasonic generator converts input AC supply into high-frequency electrical/mechanical energy. This energy then drives a piezoelectric converter which transforms the electrical energy to mechanical vibrations. The probe attached to the converter amplifies these vibrations whilst transmitting them down as ultrasonic waves. As the probe’s tip vibrates with high frequency, a cavitation is formed which causes microscopic bubbles to implode. Tremendous amount of energy is released as a result of the violent implosion of bubbles which is utilised to process the surfaces and objects within the cavitation.

Whilst the three key components described above are a prerequisite for an ultrasonic probe sonicator, following are some important accessories that can be used for sonication:

1. Replacement Tips for Standard Probes

In high-amplitude sonication settings, the probe’s tips have a tendency to erode and become less effective with extended use. If these tips are not replaced, they can burden the ultrasonic power generator. Some processing applications require titanium tips whereas others need glass probe tips. As far as the efficacy goes, glass tips wear out slowly compared to titanium ones and are generally recommended for processing liquids with abrasive materials. Tips for standard probes generally have a large diameter to process larger volumes; however, they provide lower intensity.

2. Microtip Probes

Microtip probes have smaller tip diameters and are specially designed to process small sample volumes but ones that require high intensity. These microtips are available in tapered as well as stepped-up configurations and deliver sonification wherein the energy is concentrated within a limited area. Generally used for short bursts of sonication in pulse mode, microtips need narrow vessels and samples to be chilled for best results.

3. Flowcells

Ultrasonic flowcells or chambers are ideal for mixing and dispersing applications. They offer inline or continuous, large volume, batch sample processing. The sample enters the chamber through the inlet at the bottom of the assembly and passes through the cavitation field to be ultrasonically processed. Post processing, it comes out through an outlet and can be recirculated through the cavitation for reprocessing. The cycle can repeat if necessary and the degree of processing can be controlled by adjusting the intensity of sonication as well as the flow rate.

4. Sound Enclosures

Whether used in laboratory or in a factory setting, sound enclosures diffuse and reduce the noise generated by the ultrasonic probe sonicators by approximately 20 db. This helps eliminate the inconvenience caused due to loud noise (approximately 95 db) to people around. Besides reducing noise levels generated by ultrasonicators, the enclosures made using waterproof acoustical foam come with a mounting system and coolant ports on either side. The mounting system allows the converter and the probe to be mounted on top.

Paresh Shah is a Director at Life-Care Equipments Pvt. Ltd., a leading manufacturer and distributor of a wide range of ultrasonic cleaning systems.