Proceedings of EAPAD, SPIE's 8
th
Annual International Symposium on Smart Structures and Materials, 5-8 March,
2001, Newport, CA. Paper No. 4329-74 SPIE Copyright © 2001
1
Androids: application of EAP as artificial muscles to entertainment
industry
D. Hanson
a1
, G. Pioggia
b2
, Y. Bar Cohen
c3
, D. de Rossi
b2
a
Disney,
b
U. Of Pisa, Italy,
c
Jet Propulsion Lab, Pasadena, CA.
ABSTRACT
The classic movie Metropolis (1926), which is nowadays considered a cinema milestone, has shown the possibility to
build robots called androids that are science and fiction run together to realize a dream: the human-like robot. In that
movie, Dr. Rotwang transforms a simple and cold calculating robot into the body of a beautiful woman. Robots have
often been depicted as metal creatures with cold steel bodies, but there is no reason why metals should be the only kind
of material for construction of robots. The authors examined the issues related to applying electroactive polymers
materials (EAP) to the entertainment industry. EAP are offering attractive characteristics with the potential to produce
more realistic models of living creatures at significantly lower cost. This paper seeks to elucidate how EAP might
infiltrate and ultimately revolutionize entertainment , showing some applicative examples.
Keywords : Electroactive Polymers, EAP, Actuators, Entertainment, Animatronics, Android, Anthroids Humanoid, and
Science Fiction.
INTRODUCTION
Current robots are constructed of metal or plastic frames, motors, gears, electronic circuit boards, and solid shapes that
allow producing efficient machines but inefficient human characters, bodies and faces. In this design, the main structure
of the robot is its exoskeleton . In many cases, a “skin” like material is placed over the exoskeleton but it is for
appearance only. Exploiting the properties of electroactive polymers as artificial muscles may enable the movement of
the covering skin, define the character and provide human-like expressivity. Such capabilities would offer great benefits
to the entertainment industry. Portraying androids, animatronics and animals are essential to entertainment, and for some
of the entertainment applications, long-term performance is not critical. Abundant movies use robotics and/or digital
rendering to simulate organisms; examples include A Bug’s Life , Deep Blue Sea , The Matrix , Mighty Joe Young, and
many others. EAP could significantly enhance traditional character simulation technologies, adding biological accuracy
to animatronics’ actuation [Hanson and Pioggia, 2001].
In lab tests, EAP has already shown that it can match critical properties of biological muscle [Bar-Cohen, 1999,
2000, 2001a&2001b, Zhang et al., 1999]. EAP also promises to be effective in configurations homologous to animal
musculature – a strong advantage over other forms of actuation [Full and Meijer, 2001]. Although EAP has yet to
demonstrate these capacities in character animation, recent materials breakthroughs bring the possibility tantalizingly
close. EAP materials have characteristics attractive to the entertainment industry, offering the potential to more
effectively model living creatures at significantly lower cost [Dickinson, et al, 2000]. Visco-elastic EAP materials could
provide more lifelike aesthetics, vibration and shock dampening, and more flexible actuator configurations. Moreover,
multiple studies have shown that the visco-elastic properties of animal tissue are key to locomotion and general stability.
In these regards, EAP is the only actuation technology to date that earns the moniker “artificial muscle”. To make it so,
collaboration between academia and industry will be indispensable. If EAP proves itself in entertainment, it will find
ample resources for further research and development.
1. APPLICATION OF EAP TO ANDROIDS
EAP-actuated animatronics may give birth to the darling of science fiction: the Android (or Anthroid, to be gender
neutral). Such sentient beings designed to specification would be ideal for entertainment. EAP-based anthroids could
star in movies, roam around theme parks and serve as tele-robots or interface devices for the Web. Given the likely
moderate cost of EAP actuators, making anthroids that are driven by such actuators could quickly pervade our world as
servants or even peers. Possibly, even props such as an anthroid’s clothing could be animated using this type of actuation
1
Walt Disney Imagineering, 1401 Flower Street, Glendale, CA 91221-5020, 323-468-1133 dayofid@hotmail.com
2
Facolta di Ingegneria, Centro "E. PIAGGIO", Universita di Pisa, Via, Diotisalvi, 2 56100 Pisa, Italy
3
JPL/Caltech (MS 82-105), 4800 Oak Grove Drive, Pasadena, CA 91109-8099, yosi@jpl.nasa.gov , web: http://ndeaa.jpl.nasa.gov