RoboBee is a tiny
robot capable of partially
untethered flight, developed by a research robotics team at
Harvard University. The culmination of twelve years of research, RoboBee solved two key technical challenges of
micro-robotics. Engineers invented a process inspired by
pop-up book
The term pop-up book is often applied to any book with three-dimensional pages, although it is properly the umbrella term for movable book, pop-ups, tunnel books, transformations, volvelles, flaps, pull-tabs, pop-outs, pull-downs, and more, each ...
s that allowed them to build on a sub-millimeter scale precisely and efficiently. To achieve flight, they created artificial muscles capable of beating the wings 120 times per second.
The goal of the RoboBee project is to make a fully
autonomous
In developmental psychology and moral, political, and bioethical philosophy, autonomy, from , ''autonomos'', from αὐτο- ''auto-'' "self" and νόμος ''nomos'', "law", hence when combined understood to mean "one who gives oneself one's ow ...
swarm
Swarm behaviour, or swarming, is a collective behaviour exhibited by entities, particularly animals, of similar size which aggregate together, perhaps milling about the same spot or perhaps moving ''en masse'' or migrating in some direction. ...
of flying robots for applications such as
search and rescue,
surveillance and
artificial pollination
Hand pollination, also known as mechanical pollination is a technique that can be used to pollinate plants when natural or open pollination is either undesirable or insufficient.
Method
This method of pollination is done by manually transfer ...
. To make this feasible, researchers need to figure out how to get power supply and decision making functions, which are currently supplied to the robot via a tiny tether which is integrated with the main body.
The wingspan of RoboBee makes it the smallest man-made device modeled on an insect to achieve flight.
History
For more than a decade, researchers at
Harvard University have been working on developing tiny flying robots.
The
United States Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military.
Originally known as the Adv ...
funded early research in the hopes that it would lead to stealth surveillance solutions for the battlefield and urban situations. Inspired by the biology of a
fly
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...
, early efforts focused on getting the robot airborne. Flight was achieved in 2007, but forward motion required a guideline since it was not possible to build control mechanisms on board.
UC Berkeley robotics researcher Ron Fearing called the achievement "a major breakthrough" for micro scale robotics.
The concept of micro-scale flying systems was not new. The "
DelFly
The DelFlyBradshaw, Nancy L., and David Lentink. "Aerodynamic and structural dynamic identification of a flapping wing micro air vehicle." AIAA conference, Hawaii. 2008.^ de Croon, G.C.H.E.; de Weerdt, E. ; De Wagter, C. ; Remes, B.D.W. ; Ruijsink, ...
" (3.07 g) was capable of untethered self-controlled forwards flight, while
Micromechanical Flying Insect
The Micromechanical Flying Insect (MFI) is a miniature UAV (unmanned aerial vehicle) composed of a metal body, two wings, and a control system. Launched in 1998, it is currently being researched at University of California, Berkeley., UC Berkeley. ...
research devices (0.1 kg) had sufficient power for hovering, but lacked self-sustained flight capacity.
Based on the promise of the early robotic fly experiments, the RoboBee project was launched in 2009 to investigate what it would take to "create a robotic bee colony".
Achieving controlled flight proved exceedingly difficult, requiring the efforts of a diverse group: vision experts, biologists, materials scientists, electrical engineers.
During the summer of 2012, the researchers solved key technical challenges allowing their robotic creation, nicknamed RoboBee, to take its first controlled flight. The results of their research were published in ''
Science'' in early May 2013.
Design challenges
According to the RoboBee researchers, previous efforts to miniaturize robots were of little help to them because RoboBee's small size changes the nature of the forces at play.
Engineers had to figure out how to build without
rotary motor
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force ...
s,
gears, and
nuts and
bolts, which are not viable on such a small scale.
In 2011, they developed a technique where they cut designs from flat sheets, layered them up, and folded the creation into shape.
Glue was used to hold the folded parts together, analogous to
origami.
The technique replaced earlier ones that were slower and less precise and used less durable materials.
The manufacturing process, inspired by
pop-up book
The term pop-up book is often applied to any book with three-dimensional pages, although it is properly the umbrella term for movable book, pop-ups, tunnel books, transformations, volvelles, flaps, pull-tabs, pop-outs, pull-downs, and more, each ...
s, enables the rapid production of
prototype RoboBee units.
At micro scale, a small amount of turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between ...
can have a dramatic impact on flight. To overcome it, researchers had to make RoboBee react very rapidly. For the wings, they built " artificial muscles" using a piezoelectric actuator - a thin ceramic strip that contracts when electric current is run across it. Thin plastic hinges serve as joints that allow rotational motions in the wings. The design allows the robots to generate power output comparable with an insect of equal size. Each wing can be controlled separately in real time.
The ultimate goal of the project is to make colonies of fully autonomous and wireless RoboBees. As of 2013, two problems remain unsolved. First, the robot is too small for even the smallest encapsulated microchip
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
s, meaning there is no way for the robots to make decisions. Currently, the RoboBee has onboard vision sensors, but the data requires transmission to a tethered "brain subsystem" for interpretation. Work continues on specialized hardware accelerators in an aim to solve the problem.
Second, the researchers have not figured out how to get a viable power supply on board. "The power question also proves to be something of a catch-22
''Catch-22'' is a satirical war novel by American author Joseph Heller. He began writing it in 1953; the novel was first published in 1961. Often cited as one of the most significant novels of the twentieth century, it uses a distinctive non- ...
", remarked Wood. "A large power unit stores more energy but demands a larger propulsion system
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from ...
to handle the increased weight, which in turn requires an even bigger power source." Instead the robots have to be tethered with tiny cords that supply power and directions. A recent progress in on-board power management is the demonstration of reversible, energy-efficient perching on overhangs. This allows the prototype to remain at a high vantage point while conserving energy.
Future use
If researchers solve the microchip and power issues, it is believed that groups of RoboBees utilizing swarm intelligence will be highly useful in search and rescue efforts and as artificial pollinators. To achieve the goal of swarm intelligence, the research team has developed two abstract programming languages – Karma which uses flowchart
A flowchart is a type of diagram that represents a workflow or process. A flowchart can also be defined as a diagrammatic representation of an algorithm, a step-by-step approach to solving a task.
The flowchart shows the steps as boxes of va ...
s, and OptRAD which uses probabilistic algorithms. Potential applications for individual or small groups of RoboBees include covert surveillance and the detection of harmful chemicals.
Previously, parties such as the Electronic Frontier Foundation have raised concerns about the civilian privacy impacts of military and government use of miniature flying robots. In some areas, such as the state of Texas and the city of Charlottesville, Virginia
Charlottesville, colloquially known as C'ville, is an independent city in the Commonwealth of Virginia. It is the county seat of Albemarle County, which surrounds the city, though the two are separate legal entities. It is named after Queen ...
, regulators have restricted their use by the general public.
According to the project researchers, the "pop-up" manufacturing process would enable fully automated mass production of RoboBees in the future. Harvard's Wyss Institute is in the process of commercializing the folding and pop-up techniques invented for the project.
Technical specifications
RoboBee's wingspan is , which is believed to be the smallest man-made wingspan to achieve flight. The wings can flap 120 times per second and be controlled remotely in real time. Each RoboBee weighs .
Concerns about robotic bees and sustainability
The idea that robotic crop pollination can counter the decline in pollinators has gained wide popularity recently. Researchers from the fields of bee pollination, bee health, bee conservation, and agroecology
Agroecology (US: a-grō-ē-ˈkä-lə-jē) is an academic discipline that studies ecological processes applied to agricultural production systems. Bringing ecological principles to bear can suggest new management approaches in agroecosystems. Th ...
have argued that RoboBee and other materially engineered artificial pollinators are a technically and economically infeasible solution at present and pose substantial ecological and moral risks: (1) despite recent advances, robot-assisted pollination is far from being able to replace bees to pollinate crops efficiently; (2) using robots is very unlikely to be economically viable; (3) there would be unacceptably high environmental costs; (4) wider ecosystems would be damaged; (5) it would erode the values of biodiversity; and, (6) relying on robotic pollination could actually lead to major food insecurity.
See also
* Materially Engineered Artificial Pollinators
References
External links
Robobees project homepage
''Scientific American''
article on RoboBee with videos
* — Original ''Science'' paper.
* {{cite journal , title=Perching and takeoff of a robotic insect on overhangs using switchable electrostatic adhesion , author1=Graule, Moritz A. , author2=Chirarattananon, Pakpong , author3=Fuller, Sawyer B. , author4=Jafferis, Noah T. , author5=Ma, Kevin Y. , author6=Spenko, Matthew , author7=Kornbluh, Roy , author8=Wood, Robert J. , journal=Science , date=May 2016 , volume=352 , issue=6288 , pages=978–982 , doi=10.1126/science.aaf1092 , pmid=27199427, bibcode=2016Sci...352..978G , doi-access=free - ''Science'' paper on perching
2013 robots
Unmanned aerial vehicles of the United States
Micro robots
Pollination
Robotics projects
Harvard University