Plasma is a Greek word meaning “that which is diffuse” i.e. unclear, or semi-transparent. It is also defined by physicists as “ionised matter”.
All matter is composed of atoms which are neutral. They do not carry any electrical charge. Sometimes a flash of high voltage, or heating to extreme temperature will cause the outermost electrons to become excited and these then excite electrons from neighbouring atoms. This creates a mass of ionised matter, which is called plasma.
Plasma is considered the 4th state of matter, the other three states being solids, liquid and gas, all of which are neutral in normal conditions. The plasma state is similar to the gaseous state, yet it is very different. Plasma is ionised gas, composed of free electrons and partially charged ions.
Solids and liquids can also be ionised but in order to become plasma, they would usually transform to vapour, due to the extreme temperatures required to create plasma.
When a heat source is used to excite a gas into its plasma state, it is called a thermal plasma and it gives off more heat, light, radiation and noise or vibration. Many devices have been designed to make use of these energies efficiently.
Plasmas are not always hot, they can be cold, as long as matter is ionised. For example, a Plasma TV screen is comparatively cool to touch. The outer space beyond our solar system is all plasma, more than 99% of the universe exists in plasma state.
Plasma comprises of charged active molecules and atoms. Sensitive applications of plasma, like subjecting human tissue or internal organs to plasma treatment for medical purposes is changing aesthetic medicine. This possibility is profoundly investigated by research groups worldwide under the highly inter disciplinary research field called ‘plasma medicine’.
An American chemist and physicist Irving Langmuir 1881-1957 was the first to use this term. He won the Nobel Prize in chemistry and is noted for his famous 1919 article “The Arrangement of Electrons in Atoms and Molecules”. He was one of the first scientists to work with plasmas and was the first to call these ionised gases by that name. He did so because they reminded him of blood plasma and the way the blood plasma carried corpuscles and germs is similar to how the electrified gas carries electrons and ions. Langmuir and the American quantum physicist Lewi Tonks discovered electron density waves in plasmas that are now known as Langmuir waves. Langmuir introduced the concept of electron temperature and in 1924 invented the diagnostic method for measuring both temperature and density with an electrostatic probe, now called a Langmuir probe, it’s commonly used in plasma physics. Despite this historical connection, few applications of plasma in medicine have been explored until recently. Thankfully this situation is rapidly changing. Electrical power and discharges have been used for decades in electro-surgery for blood coagulation and tissue removal. Plasma scientists have recently realised that low temperature plasmas are quite useful for various other medical treatments, including hand/skin sterilisation, wound healing, cell apoptosis/regeneration, dentistry and so on. These applications of low temperature plasmas represent an emerging and rapidly growing frontier in low temperature plasma science and technology. A deeper understanding of the nature of these phenomena is indispensable for future technological development. Fusion GT launched the first hand-held fully portable plasma generator in the UK in 2013. It is powered by a lithium battery and uses heat to generate plasma. The heat produced causes ionisation of the air in the gap between the tip of the device and the patients skin. This is akin to a bolt of lightning and causes sublimation of the tissue being treated. Sublimation is the process by which a substance is converted directly from the solid state to gas, without passing through the liquid state. As a pure plasma device, there is no need for grounding plates, as seen in devices which utilise radio-frequency. No current passes through the patient – the charge remains on the surface of the patient. This means that it is safe to use in all patients, even those with metal implants or pacemakers. Plasma provides a mechanism for risk free skin sublimation without the need for cutting, stitching or general anaesthetic. The ability of plasma to shrink tissue, causing a lifting effect has been pivotal in the development of the non-surgical blepharoplasty, one of the most popular treatments performed with this modality. However there are many more applications of plasma in aesthetic medicine.
“The shrinking effect on tissue can be applied to any part of the body and in my practice, I have successfully treated excessive skin on knees and elbows, as well as performing the technique known as mini-lifting to treat facial droop. It can also be used in an ablative way to remove benign skin lesions without scarring” (Dr Shirin Lakhani)
Plasma has been researched extensively for its antimicrobial properties, and has been used over the years in hospitals and health care for sterilisation. Its anti-microbial effect has proved effective in the treatment of active acne and also in the treatment of viral skin lesions such as herpes simplex and verrucae.
“A phenomenon I have noted during my experience with [real plasma]is that once the affected skin has been treated with Plasma, the acne lesions do not return to the treated area.” (Dr Shirin Lakhani)
Plasma is safe to use in all skin types. The plasma does not affect the basal lamina, and does not cause necrosis in the dermis. It does not stimulate or inhibit melanocytes and is therefore safe to use in all skin colours.In practice, plasma is a versatile tool with many different applications. Although it has gained popularity for the non-surgical blepharoplasty, its many other uses make it indispensable in any practice.