Person:
Helbling, Elizabeth

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Helbling

First Name

Elizabeth

Name

Helbling, Elizabeth

Filters

20192

Settings

Author's Publications: search.filters.isAuthorOfPublication.e6929ff0-2e11-41d1-b916-f2565f0410b8

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Publication
    Untethered Flight of an Insect-Sized Flapping-Wing Microscale Aerial Vehicle
    (Springer Science and Business Media LLC, 2019-06) Karpelson, Michael; Wood, Robert; Jafferis, Noah; Helbling, Elizabeth
    Heavier-than-air flight at any scale is energetically expensive. This is greatly exacerbated at small scales and has so far presented an insurmountable obstacle for untethered flight in insect-sized (mass less than 500 milligrams and wingspan less than 5 centimetres) robots. These vehicles thus need to fly tethered to an offboard power supply and signal generator owing to the challenges associated with integrating onboard electronics within a limited payload capacity. Here we address these challenges to demonstrate sustained untethered flight of an insect-sized flapping-wing microscale aerial vehicle. The 90-milligram vehicle uses four wings driven by two alumina-reinforced piezoelectric actuators to increase aerodynamic efficiency (by up to 29 per cent relative to similar two-wing vehicles) and achieve a peak lift-to-weight ratio of 1 to 1, demonstrating greater thrust per muscle mass than typical biological counterparts6. The integrated system of the vehicle together with the electronics required for untethered flight (a photovoltaic array and a signal generator) weighs 259 milligrams, with an additional payload capacity allowing for additional onboard devices. Consuming only 110–120 milliwatts of power, the system matches the thrust efficiency of similarly sized insects such as bees. This insect-scale aerial vehicle is the lightest thus far to achieve sustained untethered flight (as opposed to impulsive jumping8 or liftoff).
  • No Thumbnail Available
    Publication
    Controlled Flight of a Microrobot Powered by Soft Artificial Muscles
    (Springer Science and Business Media LLC, 2019-11) Chen, Yufeng; Mao, Jie; Zhao, Huichan; Chirarattananon, Pakpong; Helbling, Elizabeth; Hyun, Nak-seung; Clarke, David; Wood, Robert
    Flying insects capable of navigating in highly cluttered natural environments can withstand in-flight collisions because of the combination of their low inertia1 and the resilience of their wings2, exoskeletons1, and muscles. Current insect-scale (<10 cm, <5 g) aerial robots3-6 use rigid microscale actuators, which are typically fragile under external impact. Biomimetic artificial muscles7-10 capable of large deformation offer a promising alternative for actuation because they can endure the stresses caused by such impacts. However, existing soft actuators11-13 have not yet demonstrated sufficient power density for liftoff, and their actuation nonlinearity and limited bandwidth further create challenges for achieving closed-loop flight control. Here we develop the first heavier-than-air aerial robots powered by soft artificial muscles that demonstrate open-loop, passively stable ascending flight as well as closed-loop, hovering flight. The robots are driven by 100 mg, multi-layered dielectric elastomer actuators (DEA) that have a resonant frequency and power density of 500 Hz and 600 W/kg, respectively. To increase actuator output mechanical power and to demonstrate flight control, we present strategies to overcome challenges unique to soft actuators, such as nonlinear transduction and dynamic buckling. These robots can sense, and withstand, collisions with surrounding obstacles, and can recover from in-flight collisions by exploiting material robustness and vehicle passive stability. We further perform a simultaneous flight with two micro-aerial-vehicles (MAV) in cluttered environments. These robots rely on offboard amplifiers and an external motion capture system to provide power to the DEAs and control flights. Our work demonstrates how soft actuators can achieve sufficient power density and bandwidth to enable controlled flight, illustrating the vast potential of developing next-generation agile soft robots.