Hair care device and method for enhancing uptake of a topical in hair

Abstract

A hair care device for enhancing uptake of a topical in hair. The hair care device comprises a topical delivery unit for applying the topical to the hair surface, an ultrasound generator (103) for generating ultrasound at a frequency exceeding 15 MHz, wherein an ultrasound intensity is in a range between 2 W / cm2 and 100 W / cm2, and an ultrasound transducer (105) for applying ultrasound to the topical and / or the hair surface to enhance uptake of the topical by the hair.

Description

FIELD OF THE INVENTION[0001]The invention relates to a hair care device and method for enhancing uptake of a topical in hair.BACKGROUND OF THE INVENTION[0002]Applications of topicals in hair include moisturization and protection. For example, excessive heat treatments of hair can cause a reduction in moisture content and potentially lead to hair damage or even breakage. Often it is advised to use a heat protection topical to safeguard the hair from excessive heat or to moisturize the hair when it is damaged. This resonates with consumers because they want to make their hair healthier and more resistant to damage from styling. The applied topicals can be in the form of oil (e.g. Argan oil), or watery solutions that contain a mixture of ingredients. These solutions are often applied by hand into the hair pre-styling but the downside is that the user has neither control over how well the topical is distributed on the hairs, nor how well the topical penetrates into the hair structure. S...

AI Technical Summary

Benefits of technology

[0007]Embodiments of the present invention feature ways to enhance the safe and effective uptake of topicals in the hair structure by using ultrasound (15-50 MHz) induced cavitation. This provides a simple and low-cost solution to enhance topical uptake by the hair structure before or during styling and thereby reducing the risk on hair damage. The lower frequency limit of 15 MHz has been chosen to trigger the largest inclusions to be activated on the hair surface. The upper frequency limit of 50 MHz has to do with the fact that, when frequency increases, the power needed to trigger smaller inclusions will increase as well. 50 MHz is preferred as the upper frequency limit since at this frequency we can still find a reasonable combination of duty cycle and treatment time to limit thermal issues.

[0008]Embodiments of the present invention provide enhanced topical uptake for small and large tresses of hair. This is based on the insight that the indentation depth of cuticles is 0.3-2 μm, resulting in poor hair permeability for frequencies in the kHz range up to 10 MHz. In phonophoresis, the increase in tissue permeability is mostly due to cavitating bubbles: therefore, low frequencies (20-100 kHz) are usually employed. In this context, acoustic cavitation refers broadly to violent oscillations of pre-existing gas inclusions. However, the typical size of the indentation depth between cuticle scales on a healthy and undamaged / untreated hair surface is about 0.3-0.5 μm, i.e. approximately 1 cuticle cell. When stressed (particularly if bent) or damaged, the indent can be much larger, in the order of 1-2 μm. When hair is wet, we may expect gas bubbles to be trapped in these indentation depths, meaning that available gas bubbles for cavitation activity will probably be in the range of 0.3-2 μm. Therefore, using a frequency range of 15-50 MHz should ensure gentle cavitation of trapped gas bubbles in damaged and undamaged cuticle scales. The power required for inertial cavitation increases significantly at higher frequencies (from about 2 W / cm2 at 1 MHz to about 100 W / cm2 at 50 MHz). Higher power usage leads to higher temperature increases per second. If cavitation is used to increase the permeability of cuticle scales and to increase moisture uptake, cuticle scales should be closed after treatment (for instance using a conditioner or simply by surface moisturization) to avoid fast moisture loss after treatment. Alternatively, cavitation may be set at a very gentle reversible level, limiting the damage to cuticle: also to this purpose, the choice of higher frequencies (MHz range) will be beneficial.

[0010]Embodiments of the present invention provide a safer treatment, as cavitation at low frequencies requires less energy than at higher frequencies and the range of bubbles excited tends to be larger. Ultrasound at megahertz frequencies will create less inertial cavitation (mechanical index cavitation). The higher the frequency the less violent cavitation is created, thereby reducing the likelihood of mechanically damaging the hair structure.

[0011]Embodiments of the present invention provide ease of use, simple execution, low-power requirements, a small footprint, e.g. a small handheld device.

Problems solved by technology

This is based on the insight that the indentation depth of cuticles is 0.3-2 μm, resulting in poor hair permeability for frequencies in the kHz range up to 10 MHz.

Higher power usage leads to higher temperature increases per second.

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