Editing Biomimetics (section)

=== Biomimetic flying robots (BFRs) ===
[[File:Skybird.gif|thumb|Flapping wing BFR in motion|210x210px]]
BFRs take inspiration from flying mammals, birds, or insects. BFRs can have flapping wings, which generate the lift and thrust, or they can be propeller actuated. BFRs with flapping wings have increased stroke efficiencies, increased maneuverability, and reduced energy consumption in comparison to propeller actuated BFRs.<ref>{{Cite journal |last1=Zhang |first1=Jun |last2=Zhao |first2=Ning |last3=Qu |first3=Feiyang |date=2022-11-15 |title=Bio-inspired flapping wing robots with foldable or deformable wings: a review |journal=Bioinspiration & Biomimetics |volume=18 |issue=1 |pages=011002 |doi=10.1088/1748-3190/ac9ef5 |pmid=36317380 |s2cid=253246037 |issn=1748-3182}}</ref> Mammal and bird inspired BFRs share similar flight characteristics and design considerations. For instance, both mammal and bird inspired BFRs minimize [[Aeroelasticity#Flutter|edge fluttering]] and [[Wingtip vortices|pressure-induced wingtip curl]] by increasing the rigidity of the wing edge and wingtips. Mammal and insect inspired BFRs can be impact resistant, making them useful in cluttered environments.

Mammal inspired BFRs typically take inspiration from bats, but the flying squirrel has also inspired a prototype.<ref name=":2">{{Cite journal |last1=Shin |first1=Won Dong |last2=Park |first2=Jaejun |last3=Park |first3=Hae-Won |date=2019-09-01 |title=Development and experiments of a bio-inspired robot with multi-mode in aerial and terrestrial locomotion |journal=Bioinspiration & Biomimetics |volume=14 |issue=5 |pages=056009 |doi=10.1088/1748-3190/ab2ab7 |pmid=31212268 |bibcode=2019BiBi...14e6009S |s2cid=195066183 |issn=1748-3182|doi-access=free }}</ref> Examples of bat inspired BFRs include Bat Bot<ref>{{Cite book |last1=Ramezani |first1=Alireza |last2=Shi |first2=Xichen |last3=Chung |first3=Soon-Jo |last4=Hutchinson |first4=Seth |title=2016 IEEE International Conference on Robotics and Automation (ICRA) |chapter=Bat Bot (B2), a biologically inspired flying machine |date=May 2016 |chapter-url=https://ieeexplore.ieee.org/document/7487491 |location=Stockholm, Sweden |publisher=IEEE |pages=3219–3226 |doi=10.1109/ICRA.2016.7487491 |isbn=978-1-4673-8026-3|s2cid=8581750 }}</ref> and the DALER.<ref name=":3">{{Cite journal |last1=Daler |first1=Ludovic |last2=Mintchev |first2=Stefano |last3=Stefanini |first3=Cesare |last4=Floreano |first4=Dario |date=2015-01-19 |title=A bioinspired multi-modal flying and walking robot |url=https://iopscience.iop.org/article/10.1088/1748-3190/10/1/016005 |journal=Bioinspiration & Biomimetics |volume=10 |issue=1 |pages=016005 |doi=10.1088/1748-3190/10/1/016005 |pmid=25599118 |bibcode=2015BiBi...10a6005D |s2cid=11132948 |issn=1748-3190}}</ref> Mammal inspired BFRs can be designed to be multi-modal; therefore, they're capable of both flight and terrestrial movement. To reduce the impact of landing, shock absorbers can be implemented along the wings.<ref name=":3" /> Alternatively, the BFR can pitch up and increase the amount of drag it experiences.<ref name=":2" /> By increasing the drag force, the BFR will decelerate and minimize the impact upon grounding. Different land gait patterns can also be implemented.<ref name=":2" />
[[File:Insectothopter.png|thumb|193x193px|Dragonfly inspired BFR.]]
Bird inspired BFRs can take inspiration from raptors, gulls, and everything in-between. Bird inspired BFRs can be feathered to increase the angle of attack range over which the prototype can operate before stalling.<ref name=":4">{{Cite journal |last1=Kilian |first1=Lukas |last2=Shahid |first2=Farzeen |last3=Zhao |first3=Jing-Shan |last4=Nayeri |first4=Christian Navid |date=2022-07-01 |title=Bioinspired morphing wings: mechanical design and wind tunnel experiments |journal=Bioinspiration & Biomimetics |volume=17 |issue=4 |pages=046019 |doi=10.1088/1748-3190/ac72e1 |pmid=35609562 |bibcode=2022BiBi...17d6019K |s2cid=249045806 |issn=1748-3182}}</ref> The wings of bird inspired BFRs allow for in-plane deformation, and the in-plane wing deformation can be adjusted to maximize flight efficiency depending on the flight gait.<ref name=":4" /> An example of a raptor inspired BFR is the prototype by Savastano et al.<ref>{{Cite journal |last1=Savastano |first1=E. |last2=Perez-Sanchez |first2=V. |last3=Arrue |first3=B.C. |last4=Ollero |first4=A. |date=July 2022 |title=High-Performance Morphing Wing for Large-Scale Bio-Inspired Unmanned Aerial Vehicles |url=https://ieeexplore.ieee.org/document/9804870 |journal=IEEE Robotics and Automation Letters |volume=7 |issue=3 |pages=8076–8083 |doi=10.1109/LRA.2022.3185389 |s2cid=250008824 |issn=2377-3766|url-access=subscription }}</ref> The prototype has fully deformable flapping wings and is capable of carrying a payload of up to 0.8&nbsp;kg while performing a parabolic climb, steep descent, and rapid recovery. The gull inspired prototype by Grant et al. accurately mimics the elbow and wrist rotation of gulls, and they find that lift generation is maximized when the elbow and wrist deformations are opposite but equal.<ref>{{Cite journal |last1=Grant |first1=Daniel T. |last2=Abdulrahim |first2=Mujahid |last3=Lind |first3=Rick |date=June 2010 |title=Flight Dynamics of a Morphing Aircraft Utilizing Independent Multiple-Joint Wing Sweep |journal=International Journal of Micro Air Vehicles |language=en |volume=2 |issue=2 |pages=91–106 |doi=10.1260/1756-8293.2.2.91 |s2cid=110577545 |issn=1756-8293|doi-access=free }}</ref>

Insect inspired BFRs typically take inspiration from beetles or dragonflies. An example of a beetle inspired BFR is the prototype by Phan and Park,<ref>{{Cite journal |last1=Phan |first1=Hoang Vu |last2=Park |first2=Hoon Cheol |date=2020-12-04 |title=Mechanisms of collision recovery in flying beetles and flapping-wing robots |url=https://www.science.org/doi/10.1126/science.abd3285 |journal=Science |language=en |volume=370 |issue=6521 |pages=1214–1219 |doi=10.1126/science.abd3285 |pmid=33273101 |bibcode=2020Sci...370.1214P |s2cid=227257247 |issn=0036-8075|url-access=subscription }}</ref> and a dragonfly inspired BFR is the prototype by Hu et al.<ref>{{Cite book |last1=Hu |first1=Zheng |last2=McCauley |first2=Raymond |last3=Schaeffer |first3=Steve |last4=Deng |first4=Xinyan |title=2009 IEEE International Conference on Robotics and Automation |chapter=Aerodynamics of dragonfly flight and robotic design |date=May 2009 |chapter-url=https://ieeexplore.ieee.org/document/5152760 |pages=3061–3066 |doi=10.1109/ROBOT.2009.5152760|isbn=978-1-4244-2788-8 |s2cid=12291429 }}</ref> The flapping frequency of insect inspired BFRs are much higher than those of other BFRs; this is because of the [[Insect flight|aerodynamics of insect flight]].<ref>{{Cite journal |last1=Balta |first1=Miquel |last2=Deb |first2=Dipan |last3=Taha |first3=Haithem E |date=2021-10-26 |title=Flow visualization and force measurement of the clapping effect in bio-inspired flying robots |journal=Bioinspiration & Biomimetics |volume=16 |issue=6 |pages=066020 |doi=10.1088/1748-3190/ac2b00 |pmid=34584023 |bibcode=2021BiBi...16f6020B |s2cid=238217893 |issn=1748-3182}}</ref> Insect inspired BFRs are much smaller than those inspired by mammals or birds, so they are more suitable for dense environments. The prototype by Phan and Park took inspiration from the rhinoceros beetle, so it can successfully continue flight even after a collision by deforming its hindwings.