A new study on human hair has provided insights that mechanical engineers can use to develop better-performing synthetic materials. Image Credit: Flickr user Stinging Eyes
Scientists have long been aware of the strength of human hair, but until recently, the molecular properties underpinning its extraordinary properties have remained a mystery. In January 2017, researchers at the University of California in San Diego (UCSD) performed nano-level studies on human hair in order to come up with an explanation. According to the researchers, hair is able to remain strong yet flexible because it is comprised of two distinct parts: a cortex of parallel fibrils, and an amorphous matrix.
When hair is stretched, the alpha helices that make up the cortex uncoil into beta sheets, which makes it possible for the hair to be deformed without breaking, in a partially reversible way.1 The mechanical engineers at UCSD who authored the study believe that they can harness these natural properties to create innovative materials that perform better than the synthetic alternatives that are currently on the market, such as stronger body armor.2
Researchers at materials science companies can start looking to the natural world to find both inspiration and discover practical strategies for new, more improved materials with the mechanical properties that are needed to solve problems in a wide range of industries.
Exploring Natural Materials at the Nano Level
One of the main reasons why the properties of hair remained poorly understood for so long was that, until recently, scientists have simply not been able to study materials at the nano level. Today, however, new technology has finally made it possible to probe molecular and atomic structural properties at the nano level, through computer modeling and simulations. When drawing inspiration from natural materials, there are several steps of the process at which modeling and simulations software can be extremely beneficial.
- Examining the Structures of Natural Materials
Following in the footsteps of the UCSD researchers, mechanical engineers can generate leads for new synthetic materials by looking at natural systems with desirable properties. So far, scientists have also drawn from waterproof leaves3 and strong-yet-biodegradable spider silk,4 but the possibilities are endless. With modern modeling software, researchers can closely examine the molecular structures of materials found in nature in order to determine which ones are most applicable for adaptation into synthetic materials.
- Studying Critical Functional Properties
In addition to understanding the structural properties of natural materials, scientists also need to figure out how they will perform under certain conditions. As the researchers at UCSD learned, the strength and flexibility of hair no longer holds after the hair is subjected to heat levels of 140 degrees Fahrenheit, at which point stretching starts to cause permanent damage. Additionally, high humidity levels reduce the flexibility of hair by 20 to 30 percent. This is critical information for engineers to know as they seek to create synthetic versions of a natural product. It can define the limits of potential new devices, like body armor, and it can also highlight areas where engineers might tweak properties in order to improve upon the natural material.
- Designing and Testing Innovative New Materials
As researchers begin to develop new materials based on natural products, they will need to run lots of tests to make sure that they are suitable for particular applications. This could be extremely time-consuming, especially for investigations on a material’s performance under extreme conditions, like high heat, humidity or pressure. By running simulations in silico before they bring the material to the bench, researchers can get an idea of its properties and behavior before they fabricate a prototype. They can also introduce nano-level alterations to the material in order to optimize the potential product before prototyping.
Enlisting Biologists for Mechanical Engineering Research
More than ever before, the traditional lines between departments within research companies, and in the scientific community as a whole, are blurring. This is particularly relevant for mechanical engineers who are looking to understand and apply the properties of biological systems to synthetic materials. When conducting this kind of research, it can be helpful to enlist the support of biologists and environmental science experts, who can weigh in on potential new leads and point out key ways that synthetic materials could mimic natural processes. To support these discussions, modern software platforms make it possible to share research protocols and results across departmental and organizational lines, supporting robust scientific collaborations between researchers with different areas of expertise, regardless of where they are located.
BIOVIA Materials Studio is a computer modeling and simulations platform that enables scientists to examine the structures of materials at the molecular and atomic levels, and to predict properties and behavior under a wide range of conditions. It also supports information-sharing and collaboration. Contact us today to find out more about how this software can help researchers at your lab find ways to harness the properties of natural systems to solve today’s most pressing engineering problems.
- “Structure and Mechanical Behavior of Human Hair,” 2017, http://www.sciencedirect.com/science/article/pii/S0928493116319208 ↩
- Strength of Hair Inspires New Materials for Body Armor,” January 17, 2017, http://ucsdnews.ucsd.edu/pressrelease/strength_of_hair_inspires_new_materials_for_body_armor ↩
- “Lotus Leaf Inspires Waterproofing Scheme,” March 3, 2003, https://www.scientificamerican.com/article/lotus-leaf-inspires-water/ ↩
- “Adidas’ New Biodegradable Sneakers Are Made From Ultra-Strong Artificial Silk Fibers,” November 17, 2016, http://gizmodo.com/adidas-new-biodegradable-sneakers-are-made-from-ultra-s-1789055422 ↩