[interview] Stanford University Explores How Cosmetics Influence Sensory Activation and Perception — Cosmetic Victories Profile

The mind-skin connection has been a major focus in beauty innovation; and evidence of its bidirectional path continues to mount. Steventon outlined how cosmetics and skin care could even be used to improve the well-being of consumers, positioning such products under the health care umbrella.

Key to leveraging this connection (and product liking in general) is understanding how consumers perceive products — a long-drawn pursuit in cosmetics R&D. Once these dynamics are established, consumer perception could be modulated to elicit a desired mental or physical response.

These mechanisms have been the focus of Stanford University researchers, who as previously reported, were recognized as academic finalists in the Cosmetic Victories competition, sponsored by the Cosmetic Valley-ESSEC endowment fund.

Here we profile the work at Stanford University that more specifically — through partial funding by L'Oréal — conducted quantitative studies combining biomechanical tests and in vivo analysis to determine how sensory neuron activation by cosmetic products modulates perception. Ross Bennett-Kennett, Ph.D., graduate research assistant at Stanford University, explains.

Predicting Perception: Thin Films and Skin Tightness

"The innovation takes concepts and methods fundamental to the semiconductor industry and applies them to cosmetics and human sensation," he explains. "By leveraging thin film test systems and modeling, we can apply treatments to cadaveric skin and predict how that treatment will be perceived by the consumer in terms of the sensation of tightness."

According to Bennett-Kennett, the novelty of the approach is in its ability to provide insights into human perception. "The idea of linking skin tightness to drying is intuitive but really has not been demonstrated in a fundamental way before," he writes.

What's more, this approach leverages mechanical testing and modeling that per Bennett-Kennett, provides insight about how humans feel. "We were able to show that mechanical forces in our skin, upon drying, propagate from the very thin stratum corneum surface layers all the way down through the epidermis and into the dermis, where mechanoreceptors are available to 'feel' those forces."

Bennett-Kennett adds that many industries are concerned with how people experience touch; from cosmetics and personal care, to even the world of haptics and human/machine interfaces. Understanding how information in the form of touch can be transmitted through skin and how products can be used to enhance or modulate that information is paramount for innovation in these spaces.

Inspired by Nuances in Product Experiences

Project collaborators (and family) sharing a meal and discussion in Paris (L to R): Gustavo Luengo (L’Oréal), Ross Bennett-Kennett (Stanford), Bree Bennett-Kennett, Barbara Lynch (L’Oréal) and Anne Potter (L’Oréal)Image courtesy of Ross Bennett-Kennett

The idea for this project, Bennett-Kennett reports, came from decades of research at the Dauskardt Lab at Stanford University exploring the mechanical behavior of the human stratum corneum. 

"It's no secret that dry skin feels tight and that hydrating the skin feels better. But there are nuances in the differences between product A and product B and how a consumer perceives the skin treatments. The answer to those nuances is something very important to a company like L’Oréal, who helped to fund and supported this work through collaboration."

Collectively, the experience from industry R&D teams and the experience from decades of academic work came together to make this possible. 

Challenges of Measuring the Illusive Sense of Touch 

One major challenge in this work was developing an approach to measure something that seems so accessible to many of us — touch — but is also illusive from a fundamental scientific perspective. 

"It was not a simple problem to take skin and probe how it mechanically behaves after a treatment," explains Bennett-Kennett. "We had to build a custom micromechanical test setup as well as a custom drying chamber to make this possible."

He continues, "Unlike what sci-fi would have us believe, it is an immense challenge to interface the soft and lively world of human biology with the hard and cold world of metals and technology." 

According to Bennett-Kennett, the experience and knowledge at Stanford in working with and even developing such cutting-edge technological systems is what drove the success of this work.

At the Interface of New Perspectives

In terms of what Bennett-Kennett hopes to gain from being recognized as a Cosmetic Victories finalist, he highlights inspiring others to view challenges through novel perspectives.

"... I want to thank the Cosmetics Valley organization and the event team there for putting on such a wonderful evening celebrating science and innovation in this space," he expressed. "I anticipate, or rather hope, that this opportunity helps those in attendance to start looking at their challenges from a different perspective — and maybe learn something from an outsider like a metallurgical engineer from California."

He added that many experts can get "stuck" in their focus as scientists and can become very specialized, very quickly. "I believe that the greatest innovations occur at the interfaces, and without the collaboration of ideas and the inclusion of outsiders, those interfaces can’t form."

Bennett-Kennett hopes this work inspires new thought across the industry about how to approach fundamental questions. "And I hope anyone I met at the event feels empowered to reach out and stay in touch with me or the lab at Stanford," he noted. "I anticipate that new partnerships formed at these interfaces will continue to push this industry forward."