H. Tronnier, M. Wiebusch, U. Heinrich

Frictiometry on human skin

Institute for Experimental Dermatology, University Witten/Herdecke, 58455 Witten, Germany

Background:
The state and function of human skin can be quantified by numerous non invasive test methods (1).
There are, however, still no valid methods to measure the tactile properties of the skin surface and thus to quantify the state of the skin an the one hand, and to determine the negative and positive effects of tactile influences an the other hand.

Objective:
In the following, a measuring device with variable parameters is described. With this device the afore mentioned objectives are to be reached and examples for the practical application of the method will be given. If need be, this can be done in combination with a method for the determination of the skin physiologically relevant surface parameters (2).

Methods:
The measuring device (Friktiometer®) (Producer: Courage und Khazaka, electronik GmbH, Mathias Brüggen Str. 91, 50829 Köln) consists of a sensor, which is to be placed onto the skin, a steering unit and a monitor.

The measuring head contains a DC micro motor, which is controlled rotationally (50 80 revolutions/min) onto which a variable Teflon sensor head (0 10 mm) can be placed via an exchangeable spring. The skin contact force of the rotating sensor is determined inductively with the spring constant and the compression. The torque, i.e. the circular friction an the skin surface, is measured via the motor load current and is shown as a voltage drop.

Results:
Depending an the surface structure there are higher values for dry and wrinkly skin than for normal skin.

While water increases the frictionary resistance of the skin, depending an their galenic (lipid proportion) skin care products lead to "smoothing" of the skin. This is more pronounced an dry than an normal skin.

The frictionary resistance an dry skin is lower than an moist skin.

The effect of a W/O emulsion is not only greater, but it also lasts longer than the effect of an O/W emulsion.

Conclusion:
A new measuring device for the defined friction of the skin (Friktiometer°) is described and its possible applications are shown with examples. There were the following findings: The frictionary resistance of the skin is determined by the state of its surface structure. Skin care products improve the frictionary resistance time dependently.

The frictionary resistance is increased an moist skin.

Depending an the material and e.g. their moistness, textiles, fleeces, etc. increase the frictionary resistance of the skin.

In comparison to an untreated sample, paper tissues containing additives, for instance, can reduce the frictionary resistance and thus also irritation.

The SELS procedure facilitates a differentiated analysis of friction irritations.

References:
1. J. Serup, G.B.E.Jemec (Herausgeber): Handbook of non invasive Methods and the skin; CRC Press (1995)
2. H. Tronnier: Ergebnisse der Hautoberflächenanalyse mit SELS; Kosm. Medizin 19.278 283 (1998)
3. H. Tronnier, M. Wiebusch, U. Heinrich: Friktiometrie an der menschlichen Haut; Kosm. Medizin 22.228 235 (2001)

nach oben

Copyright © 2000 - 2025
Institute for Dermopharmacy GmbH
webmaster@gd-online.de