By the Electric Flight crew
The World’s Smallest
A work in progress, the Piccolissimo (Italian for “littlest”) is con- sidered to be the smallest self-contained micro aerial vehicle (MAV) to date. It is the work of Matthew Piccoli, who is currently a fifth-year doctoral candidate at the University of Pennsylvania.
Matthew’s research focuses on MAVs with underslung propellers, their
control (particularly of their brushless motors), and their construction,
and he designed and fabricated all parts of the Piccolissimo. Matthew
used an analytical model program to design the body-stabilizer blades,
then used Solidworks 3D to design the rest of the body. From there, the
micro drone was 3D-printed using the university’s ProJet 6000 HD. For
final assembly, Matthew hand-soldered the circuitry, which consisted of
an ATtiny10 8-bit microcontroller, a MOSFE T transistor, an IR LED, and a
We had a chance to chat with Piccolissimo’s designer and here’s what
Elecric Flight: How does it work?
Matthew Piccoli: ;e Piccolissimo uses passive stability to remain in the
air. ;e circuitry pulses its motor once per body rotation, which allows the
drone to translate into a stable hover. Passive stability also allows the tiny
aerial vehicle to use fewer actuators, computation, and sensors to stay
Tell us what you’ve learned during this research project.
We’ve been able to come up with a method to passively stabilize any
vehicle without angular momentum by adding specifically sized and
placed stabilizer sails. Hovering and flying vehicles usually require four
actuators/rotors (like with quadcopters), but by taking advantage of the
vehicle’s dynamics and aerodynamics, we can build a flier with fewer
parts, with simpler electronics, and at a lower cost.
What about control?
We now have two versions. ;e mini version is controllable only in altitude.
;e vehicle’s passive stability ensures that the vehicle orientation
remains upright (a lot like how the vertical stabilizer on an airplane
attempts to make the plane fly along the longitudinal axis), which is why
we can get away with only one motor.
;e maneuverable version o;sets this motor from the center of mass
so that the force from the propeller always applies a torque to the vehicle
body. Since the body is spinning quickly, this torque cancels out if the
propeller’s thrust stays constant. But if we pulse the speed of the motor
at the same angle of rotation (for example, every time the vehicle body is
“facing” north), then the torque doesn’t cancel out and that lets it steer.
How did your research project get started? What advantages were you
We first set out to build the world’s simplest flying vehicle, which we
subjectively think is fewer motors and sensors. We accomplished this a
couple of years ago and realized that simple vehicles could be made very
small. We can make Piccolissimo half the linear size and a quarter the
planform area of the quadrotor that we take the parts from since we only
use one motor and propeller instead of four.
What’s on the horizon for your project?
Piccolissimo has a lot of short-term plans and far-out
possible uses. In the short term, we’re working to
make them able to fly in swarms so that many can
work in teams to cover large areas. ;e size and
low cost of Piccolissimo would allow researchers
to use hundreds or even thousands in space-
In the long term, they could be used for
atmospheric sensing (similar to weather
balloons), search and rescue (they have enough
payload for a camera), and aerial light shows (each
Piccolissimo would be a “pixel”). ; PH
A r m
;e Piccolissimo has a 3D-printed body
that includes the airflow sails and battery-attachment pockets molded as part of the
Shown hovering just
above a tabletop, this
super-micro single-motor drone uses
passive stability to
remain in stable flight.