Loading the player ...
- Offer Profile
- The goal of the Biomimetic
Millisystems Lab is to harness features of animal manipulation, locomotion,
sensing, actuation, mechanics, dynamics, and control strategies to radically
improve millirobot capabilities. Research in the lab ranges from fundamental
understanding of mechanical principles to novel fabrication techniques to
system integration of autonomous millirobots. The lab works closely with
biologists to develop models of function which can be tested on engineered
and natural systems. The lab's current research is centered on fly-size
flapping flight, and all-terrain crawling using nanostructured adhesives.
Biologically Inspired Synthetic Gecko Adhesives
- Geckos have the remarkable ability to run at any
orientation on just about any smooth or rough, wet or dry, clean or dirty
surface. The basis for geckos' adhesive properties is in the millions of
micron-scale setae on each toe of the gecko form a self-cleaning dry
adhesive. The tip of each seta consists of 100 to 1000 spatulae only 100
nanometers in diameter. Our interdisciplinary team of biologists and
engineers has been working since 1998 developing models for how the natural
nanostructures function in a hierachical combination of spatulae, spatular
stalks, setal stalks, setal arrays, and toe mechanics, and developing
nanofabrication processes which allow large arrays of hair patches to be
GSA Adhesive Material Limits
- HDPE and PP fibrillar arrays have shear adhesion stress
(0.3 MPa) sufficient to deform the fibers. Hence the fiber material strength
is a limit to greater adhesion strength. Surprisingly, the GSA maintained
54% of original stress in spite or marked deformation over 10,000 cycles.
Gecko Tire for Model Car
- Micro and nanofiber structures are designed to provide
high friction and adhesive forces through mechanical control of surface
Combined Lamellar Nanofibrillar Array
- Lamellar structures act as base support planes for
high-aspect ratio HDPE fiber arrays. Nanofiber arrays on lamella can adhere
to a smooth grating with 5 times greater shear strength than flat nanofiber
Hybrid CoreShell Nanowire Connectors
- Arrays of parylene coated Ge nanowires connect with
themselves to form a reusable connector. Uniquely, NW chemical connectors
exhibit high macroscopic shear adhesion strength (1.6 MPa) with minimal
binding to non-self-similar surfaces, anisotropic adhesion behavior (shear
to normal strength ratio 25), low preloading, reusability, and efficient
binding for both micro- and macroscale dimensions.
Directional Adhesion of Angled
- Angled polypropylene microfibers show strong directional
adhesion effects, with shear strength in direction of fibers 45 times larger
than sliding against fiber directions. Angled fibers also show normal
adhesion without shear load, unlike vertical fibers.
Self Cleaning Gecko Adhesive
- First synthetic gecko adhesive which cleans itself during
use, as the natural gecko does. After contamination by microspheres, the
microfiber array loses all adhesion strength. After repeated contacts with
clean glass, the microspheres are shed, and the fibers recover 30% of their
Directional gecko adhesive
- First easy attach, easy release, and directional
synthetic gecko adhesive using hard polymer microfibers. Microfiber array
using 42 million polypropylene microfibers per square centimeter. Patches
can support 9 N/sq.cm. in estimated contact region with preload of just
- The goal of this work is to develop high performance ambulating milli-robots using minimal actuation and passive stabilization mechanisms, combined with onboard high level control.
Legged systems provide some key performance advantages compared to wheeled
systems. In a legged system the feet are not continually in contact with the
ground, whereas wheels require a continuous path of support. This enables
legged organisms and robots to traverse challenging terrain. Some legged
systems (biological and man-made) can overcome obstacles that are more than
three times taller than the hip height of the system while wheels are
limited to obstacles no higher than one radius. Finally, and perhaps most
interesting is the dynamic behavior of legged organisms seen in nature. Many
legged animals exhibit dynamically, self-stabilizing behavior. That is, the
passive mechanical properties of the systems are tuned to naturally reject
disturbances which might otherwise cause unstable behavior in the system.
OctoRoACH:Dual Drive MilliRobot
- The OctoRoACH robot has a mass of less than 30 grams, and
includes the ImageProc CPU with gyro, accelerometer, radio and camera, is
capable of locomotion in rough surfaces. Robot designed by A. Pullin.
DASH 16 gram Hexapedal Robot
- Using compliant fiber board as structural material, and a
single main driver motor, the DASH robot is capable of 15 body lengths per
second on flat surfaces. The structure is resilient and survives ground
impact at terminal velocity of 10 meters per second.
DASH: A Dynamic 15g Hexapedal Robot, IROS 2009.
The RoACH Robot
- In the Biomimetic Millisystems Lab we have combined our
expertise in building millirobots with an interest in legged systems to
build what we believe is the smallest untethered, legged robot to date - a
2.5 gram legged robot called the Robotic Autonomous Crawling Hexapod (RoACH).
This robot makes use of the Smart Composite Microstructures fabrication
process and integrated shape memory alloy (SMA) wire actuators. All power,
control, and communication electronics are carried onboard and the entire
robot is powered with a 20maHr Lithium-polymer battery from the Full River
Prototyping Folded Robots
- As the size of a robot decreases, the ratio of its
surface area to its volume increases. Because the mass of a robot is
proportional to its volume, the increase in this ratio means that surface
forces (electrostatic attraction, for example) become large compared to
inertial forces. So, as robots (and machines in general) become smaller,
friction in their moving parts can become a major source of energy loss,
wear, and unpredictable behavior. In the Biomimetic Millisystems lab, we
have developed a process called "Smart Composite Microstructures" (SCM) that
enables us to build small, strong, lightweight, robots and structures whose
ability to move comes from bending of compliant polymer hinges that connect
rigid links made from carbon fiber and other composites. These structures
are made as single flat pieces and are folded up to form more complicated
shapes and linkages. They can also be integrated with smart actuators like
piezoelectrics and shape memory alloy to provide motion.
15 gram SMA driven robot, constructed from poster board
2.5 gram SMA driven robot with integrated electronics
Rapidly prototyped scaled up version of RoACH robot
using fiber glass.
- Flapping flight provides the high maneuverability
necessary for operation in a partially structured indoor environment. To
achieve robust intelligence for tasks such as search and indoor navigation,
the maneuverability of the ornithopter will be combined with a learning
approach which makes minimal assumptions about the nature of disturbances
and obstacles. This approach will develop optimal control policies for
single or multiple vehicles. Based
on globally optimal distributed reinforcement learning, we propose to
develop algorithms for a set of ornithopters to cooperate in sensing and
navigation among unmodelled obstacles such as doors and walls. Our research
will be verified with full three dimensional dynamic simulation, a
multi-tethered laboratory test-bed, as well as with actual indoor flying
Prof. Stuart Russell, Computer Science Division, UC Berkeley
Prof. Sunil Agrawal Mechanical Systems Laboratory, Univ. of Delaware
Prof. Robert Dudley, UC Berkeley
Flight Control for Target Seeking by 13 gram Ornithopter
- We demonstrate autonomous flight control of 13 gram
ornithopter capable of flying toward a target without any remote assistance.
For this demonstration, we have developed a closed-loop attitude regulator
for the ornithopter using onboard sensing and computational resources.
BOLT: Bipedal Ornithopter for Locomotion Transitioning
- Bolt is a 13 gram ornithopter with legs for mixed-mode
locomotion. In running modes, wings provide passive stability. With wing
assisted running, BOLT can run at 2.5 m/sec while maintaining ground
contact. IROS 2011.
Altitude Regulation of iBird
- We identify free flight aerodynamic forces at a stable
equilibrium point of an ornithopter and compare them with the tethered
flight aerodynamic forces. We developed a closed-loop altitude regulation
for the ornithopter using an external camera and onboard electronics. The
results show that the tethered aerodynamic force measurement of a 12 gram
ornithopter with zero induced velocity underestimates the total flight force
by 24.8 mN.
Image Proc 2.2 CPU
- Image Proc 2.2 design revision by Stan Baek. Board
contains cell phone, gyro, accelerometer, 802.15.4 radio, and 2 channel
motor driver in 1.4 grams.
- Commercially available iBird hover capable ornithopter
equipped with ImageProc dsPIC33 CPU board. Total mass 12 grams.
Efficient Resonant Drive of Flapping
- A model for a battery-driven DC motor driving a crank is
developed, which shows in experiment a 30% reduction in required power when
driven in resonance.
- Commercially available VAMP ornithopter with custom low
mass electronics. Total mass is approximately 13 grams, including Bluetooth
and cell phone camera.
PIC CPU with Omnivision
Example processed image data from ornithopter showing
average optical flow