Study finds wrinkles deepen as skin contracts with age

Wrinkles form when the skin stretches in one direction and contracts in the other, causing it to buckle, and that effect increases with age, confirmed research from Binghamton University, US.

The study, published in the Journal of the Mechanical Behavior of Biomedical Materials, aimed to validate the physical mechanism of age-induced skin wrinkling using real human skin tissue under lifelike tension.

It found that as skin ages, transverse contractile strain increases during stretching, leading to deeper and wider wrinkles forming.

The research team used a novel tensile testing setup to simulate natural skin loads and analyzed how mechanical strain translated into surface wrinkles. They observed that these wrinkles align with the dominant direction of collagen fibers and become more severe as the skin loses elasticity over time.

“In terms of implications, I believe that understanding the physical problem of wrinkling and how it occurs will allow us to understand better how to slow it down and alleviate it,” associate professor Guy German, senior author of the study, tells Personal Care Insights.

From a product development standpoint, understanding the mechanistic origins of wrinkles opens new avenues for innovation.

Anti-aging formulations and treatments could focus beyond collagen regeneration to target the dermis’ resistance to transverse contraction, and enhance skin hydration to reduce poroelastic volume loss.

“Knowing the physics behind wrinkling gives us a clearer path forward,” says German. “We now know that minimizing transverse contraction and maintaining dermal elasticity may be key strategies in wrinkle prevention.”

“We hope this work provides useful insight into what is important when trying to tackle skin-related anti-aging.”

Straining human skin

To explore the mechanics behind wrinkle formation, the researchers acquired full-thickness human skin samples from donors aged 16 to 91. They used histological mapping to determine the dominant collagen fiber orientation in each sample.

They then cut strips of skin parallel and perpendicular to this fiber direction, and used a low-force tensometer to apply a consistent load of 2.2 newtons, mimicking the internal stress conditions. Samples were held under tension for 40 minutes, allowing the tissue to relax and adopt its post-strain configuration.

Wrinkles align with the dominant direction of collagen fibers and become more severe as the skin loses elasticity.Throughout the experiment, researchers recorded deformations and later examined the skin’s surface using digital imaging and silicone casting to quantify wrinkle depth, width, and tortuosity (how “wavy” the wrinkle is).

Additionally, the team measured density changes to determine whether stretched skin expelled water or other matrix materials, which is a sign of poroelastic volume loss under strain.

Skin responds to internal forces

The study confirmed that older skin does not stretch more in the axial direction under equal loading but contracts significantly more in the transverse direction. This contraction increased with age for both fiber-aligned and perpendicular samples.

Aged samples indicated volume loss under tension, likely due to fluid being squeezed from the tissue.

This sideways contraction under longitudinal stress causes the skin surface to buckle, which the researchers linked to wrinkle formation. They confirmed that the wrinkles consistently formed along the direction of collagen fibers.

When quantifying wrinkle morphology, they found that wrinkles in older skin were both deeper and wider. Tortuosity decreased with age, suggesting that aged skin forms straighter, more prominent folds.

These characteristics align with known age-related changes in skin structure, including dermal thinning, collagen loss, and stiffening.

Together, these biomechanical changes help explain why wrinkles become more pronounced with age, not simply because of gravity or expression, but because of the way skin responds to internal forces.