Christopher Berkey

Research Interests

Cutaneous Wound Formation and Protection Strategies

Partial-thickness cutaneous injury widely distributed over exposed or lightly covered body locations, such as the face and extremities, poses a significant risk of bleeding, infection, function loss, and extensive scarring. This type of skin damage is commonly observed after impact with accelerated debris clouds caused by blast weaponry, though civil and industrial accidents with explosives or compressed gas can also result in these injuries. There exist limited personal protective equipment (PPE) options to protect the head, face, neck, and extremities from this damage without restricting mobility.

My research aims to reveal the currently unknown connection between cutaneous wound formation, projectile attributes (kinetic energy, shape, orientation, etc.), and skin structure to enable injury treatment and prevention. I employ a gas-charged kinetic impact system to perform impact tests on near-live human skin tissue using selected projectiles at differing impact angles and energies. I image the impact damage process using high-speed video and characterize the resulting wound with digital microscopy. Findings have revealed key impact parameters and skin structural components relevant to the type and severity of damage, thus elucidating PPE design principles.

Using these principles, I have also designed several prototype adhesive armor appliques and quantitatively assessed their protective ability. These appliques reduce damage while being thin, breathable, and flexible to support user comfort and wearability. Adhesive and mechanical properties of the appliques are quantitatively characterized with thin-film mechanical analysis techniques, and I have assessed applique wearability and comfort under daily-life conditions via a Stanford IRB-approved human trial. Research is underway to continue optimizing these prototype appliques with various materials.

Design of Skin-Care Formulations for Positive Health and Consumer Perception Outcomes

Additional research focuses on the biomechanical properties of the outermost layer of human skin known as the Stratum Corneum (SC). This critical layer moderates the diffusion of water and skin-treatments, provides local mechanical stiffness to the skin, and guards against environmental insults such as UV light or microbes. Skin damage and consumer perception of discomfort result from a compromised SC barrier that has elevated levels of biomechanical stress and stiffness due to excessive moisture loss or environmental exposures.

My work aims to understand these biomechanical changes of the SC and characterize the beneficial mechanisms of skin-care treatments, to provide a rational basis for the design of advanced skin-care formulations. I utilize thin-film mechanics assays adapted for biological tissue to quantify changes in SC stress, stiffness, and cohesion after negative or positive exposures. Spectroscopic techniques such as FTIR, UV-absorption, and Raman microscopy enable me to analyze changes in the structure and organization of SC components that drive shifts in mechanics. I have also developed a mathematical model that predicts the diffusion of water or skin-care molecules across the SC and the resulting changes in stress, thus enabling a new understanding of causes behind dry skin damage and treatments. Current projects seek to reveal the individual and synergistic effects of ingredients in skin-care formulations.

Awards

• 1st Prize in the American Society for Materials Undergraduate Design Competition (2014)
• University of Maryland Dinah Berman Memorial Award (2013) 
• University of Maryland President's Scholarship (2010-2014)