Biomimicry encompasses the study of nature and natural phenomena to understand their underlying mechanisms and apply them to benefit science, engineering, and medicine. Forward-thinking companies are leveraging the R&D work completed by nature to explore the largely untapped market potential of bioinspired innovation. Examples of bioinspired products include the shapes of airplanes inspired by birds, Velcro fasteners inspired by burrs, solar cells inspired by photosynthesis, and adhesives inspired by mussels to name but a few.
In addition, biomimetic innovation can extend beyond simply using natural properties as an inspiration for innovation. The realistic gains that affect the industry due to biomimetic innovation include optimizing designs to eliminate waste and minimizing research expenses.
In order to understand the impact that biomimetic studies have had in the research field, the Da Vinci Index was developed by The Fermanian Business & Economic Institute. This index provides a measure of activity in the field of bioinspiration in the U.S. by monitoring four areas of data: number of scholarly articles, number of patents, number of grants, and dollar value of grants. The same institute estimates that biomimicry innovation would account for circa $425 billion by 2030.
What is a hydrogel?
Once such material that has been the subject of extensive research for commercial applications is a hydrogel. Hydrogels are three-dimensional networks of interconnected polymer chains that maintain their structure while being predominantly composed of water. Hence, they can be formulated to closely mimic biological tissues. Taken a step further, hydrogels can be functionalized with other molecules in order to respond to external stimuli, such as light and electric fields, in order to release cargo on demand!
Due to the customizable biocompatible properties of hydrogels, many exciting innovations have been nearing commercialization or have recently become commercialized. Below, we highlight a few such developments.
Portable 3D “Skin” Printer
Hydrogels have often been explored as wound dressings that can interface with the skin. Recently, a team of researchers at Toronto developed a machine that prints a “bio-ink” hydrogel filled with skin cells, collagen, and fibrin, a protein that helps heal wounds.
When the new device prints over a deep wound, it can set in place within two minutes. Skin grafts, in which healthy skin is placed over deep wounds, often cannot cover an entire wound due to an insufficient amount of available skin. As a solution, a handheld “skin printer” could be utilized to fully cover wounds, help the skin better heal and protect the patient from infections.
The research is still in early stages and will involve more animal testing before it can move to human trials. One challenge to overcome is ensuring enough skin cells are available to print since it takes time to grow the cells. Hence, the researchers are working on gel structures that require as few cells as possible.
Male contraceptives:
Another interesting application area for hydrogels that is nearing commercialization includes male contraceptive devices. A new contraceptive, called Vasalgel, is injected into the vas deferens (the tube that carries sperm from the testicle to the urethra), where it forms an adhesive hydrogel. This hydrogel acts as a barrier, blocking sperm from flowing out of the vas deferens. When desired, the Vasalgel can be dissolved and flushed out to restore sperm flow. The recent success of the contraceptive procedure in male monkeys indicates that human men may be up next in clinical trials.
Another company competing in this space, Contraline, has developed a technique to inject the gel that does not require surgery. Contraline will conduct clinical trials beginning in 2019 and hopes to be on the market by 2021, according to CEO Kevin Eisenfrats.
ClearSight and Sharklet:
Contact lenses are a classic example of commercialized hydrogel technology. Historically, innovations for these devices have involved reducing discomfort by integrating polymer systems that enable more oxygen to pass through to the cornea while maintaining a soft, hydrated state or by preventing adsorption of unwanted molecules onto the lens. However, new types of functionality for contact lenses inspired by nature are on the horizon.
Sharklet has developed a micropatterning technique to create surface coatings that mimics the texture and, hence, antifouling and antibacterial properties of shark skin. The Sharklet surface is comprised of millions of microscopic features arranged in a distinct diamond pattern. The structure of the pattern alone inhibits bacteria from attaching, colonizing and forming biofilms. The amazing part is that Sharklet does not contain toxic additives or chemicals and does not require antibiotics or antimicrobials. Utilizing this technology, Clearsight has developed an intra-ocular lens that prevents the adsorption of epithelial cells after cataract surgery. This innovation mitigates the risk of secondary cataract surgery, which is required by nearly a quarter of patients after their initial surgery.
Contact lenses as drug delivery devices:
The next iteration of contact lens functionality will be the ability to utilize contact lenses to control the delivery of drugs to the body. Advances in material design and processing are enabling the possibility of using contact lenses to promote patient noncompliance and provide efficient and sustained drug release to the cornea.
Final thoughts:
The interactions between the materials and systems found in nature provide a deep well of inspiration for innovation, and companies can benefit by using these designs to reduce the time and costs associated with technology and product development and to introduce new and more efficient functionalities into their product line. Although bioinspired innovation has influenced various application areas from filtration to energy, textiles and plastics, various industrial challenges have yet to be overcome by leveraging biomimetic design strategies. Taken a step further, one can begin to imagine how to develop materials that exhibit properties and achieve functionalities that are not found in nature: metamaterials.
