Editing Biomimetics (section)

=== Adhesion ===

==== Wet adhesion ====
Some amphibians, such as tree and [[torrent frog]]s and arboreal [[salamander]]s, are able to attach to and move over wet or even flooded environments without falling. This kind of organisms have toe pads which are permanently wetted by mucus secreted from glands that open into the channels between epidermal cells. They attach to mating surfaces by wet adhesion and they are capable of climbing on wet rocks even when water is flowing over the surface.<ref name=":5" /> [[Tire]] treads have also been inspired by the toe pads of [[tree frog]]s.<ref>{{Cite web|url=http://iopscience.iop.org/0953-8984/19/37/376110|title=ShieldSquare Captcha|website=iopscience.iop.org}}</ref> 3D printed hierarchical surface models, inspired from tree and torrent frogs toe pad design, have been observed to produce better wet traction than conventional tire design.<ref>{{Cite journal|last1=Banik|first1=Arnob|last2=Tan|first2=Kwek-Tze|date=2020|title=Dynamic Friction Performance of Hierarchical Biomimetic Surface Pattern Inspired by Frog Toe-Pad|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/admi.202000987|journal=Advanced Materials Interfaces|language=en|volume=7|issue=18|pages=2000987|doi=10.1002/admi.202000987|s2cid=225194802 |issn=2196-7350}}</ref>

Marine [[mussel]]s can stick easily and efficiently to surfaces underwater under the harsh conditions of the ocean. Mussels use strong filaments to adhere to rocks in the inter-tidal zones of wave-swept beaches, preventing them from being swept away in strong sea currents. Mussel foot proteins attach the filaments to rocks, boats and practically any surface in nature including other mussels. These proteins contain a mix of [[amino acid]] residues which has been adapted specifically for [[adhesive]] purposes. Researchers from the University of California Santa Barbara borrowed and simplified chemistries that the mussel foot uses to overcome this engineering challenge of wet adhesion to create copolyampholytes,<ref>{{Cite journal|last1=Seo|first1=Sungbaek|last2=Das|first2=Saurabh|last3=Zalicki|first3=Piotr J.|last4=Mirshafian|first4=Razieh|last5=Eisenbach|first5=Claus D.|last6=Israelachvili|first6=Jacob N.|last7=Waite|first7=J. Herbert|last8=Ahn|first8=B. Kollbe|date=2015-07-29|title=Microphase Behavior and Enhanced Wet-Cohesion of Synthetic Copolyampholytes Inspired by a Mussel Foot Protein|journal=Journal of the American Chemical Society|volume=137|issue=29|pages=9214–9217|doi=10.1021/jacs.5b03827|issn=0002-7863|pmid=26172268|bibcode=2015JAChS.137.9214S |s2cid=207155810 |url=http://www.escholarship.org/uc/item/9qd4s083}}</ref> and one-component adhesive systems<ref>{{Cite journal|last1=Ahn|first1=B. Kollbe|last2=Das|first2=Saurabh|last3=Linstadt|first3=Roscoe|last4=Kaufman|first4=Yair|last5=Martinez-Rodriguez|first5=Nadine R.|last6=Mirshafian|first6=Razieh|last7=Kesselman|first7=Ellina|last8=Talmon|first8=Yeshayahu|last9=Lipshutz|first9=Bruce H.|date=2015-10-19|title=High-performance mussel-inspired adhesives of reduced complexity|journal=Nature Communications|volume=6|pages=8663|doi=10.1038/ncomms9663|pmc=4667698|pmid=26478273|bibcode=2015NatCo...6.8663A}}</ref> with potential for employment in [[nanofabrication]] protocols. Other research has proposed adhesive glue from [[mussel]]s.

==== Dry adhesion ====
Leg attachment pads of several animals, including many insects (e.g., [[beetle]]s and [[Fly|flies]]), [[spider]]s and [[lizard]]s (e.g., [[gecko]]s), are capable of attaching to a variety of surfaces and are used for locomotion, even on vertical walls or across ceilings. Attachment systems in these organisms have similar structures at their terminal elements of contact, known as [[seta]]e. Such biological examples have offered inspiration in order to produce climbing robots,{{Citation needed |date=June 2022}}<!-- originally pointed to New Scientist main website, probably a good science news reference available there --> boots and tape.<ref>{{cite web|url=http://www.stanford.edu/group/mota/education/Physics%2087N%20Final%20Projects/Group%20Gamma/gecko.htm|title=Gecko Tape|publisher=[[Stanford University]]|access-date=17 July 2014|archive-date=23 June 2013|archive-url=https://web.archive.org/web/20130623011227/http://www.stanford.edu/group/mota/education/Physics%2087N%20Final%20Projects/Group%20Gamma/gecko.htm|url-status=dead}}</ref> [[Synthetic setae]] have also been developed for the production of dry adhesives.