Novel Perching Mechanism to Conserve Energy for Small Aerial Robots

At a Glance

Researchers at Colorado State University have developed a light-weight and energy-efficient mechanism to enable perching and grasping capabilities in aerial robots. It is easy to close, stable to hold, and easy to adjust, allowing the ability to perch on trees, powerlines, and the like, and enabling these devices the invaluable feature to rest while maintaining desired heights for monitoring (without flying).


There is a growing popularity of small aerial vehicles in recreational, scientific, and military applications. However, small aerial robots, especially those with multiple rotors, have a limited flight time. Depending on the size and power requirements, flight times can range from 10 minutes to 1 hour. One possible solution is to allow aerial robots to land or perch on an object (e.g., trees, power lines, or roof) so that they can save and even harvest energy instead of hovering in the air; meanwhile, they can still monitor or surveil an interested area. However, successful perching for aerial robots is challenging since it involves several important parts including mechanical perching mechanism design, flight state estimation, motion planning and control.


This novel mechanism for perching includes a bistable gripper that can switch between an open state and a closed state. Multiple fingers will grasp and release objects when switching between states. The closing mechanism is triggered by the impact force between the gripper and perching object, while transitioning to an open state can be triggered by resistance wires used to heat the fingers or a motor-driven lever system. Additionally, the design allows for clipping, using friction to hold the robot’s weight and grasp onto potentially larger and more diverse objects.

Uniquely, the mechanism for perching and grasping is constructed of a lightweight 3D-printed Polylactic acid (PLA) material and commercially available silicone tubes for compliant joints.  Such a design allows for rapid and economic exploration of different size and characteristics of variations in mechanism.  Mathematical models have been established that characterize the activation forces necessary for proper operation.  These models also formulate basic design guidelines to achieve desired activation forces based on expanded requirements from perching and grasping.


  • Easy to close: activation force is small enough for small aerial robots to exert
  • Stable to hold: activation force at closed state is (1) large enough to hold the weight of an aerial robot during perching, and (2) strong enough to grasp the weight of various payloads
  • Easy to adjust: the gripper is easily adjusted for both differing sizes of aerial robots and payload weights
  • Light weight and economical: made of 3D-printed material
  • Energy efficient: perching allows for rest and recharging of aerial robots
  • Versatile installation: Can be installed above or below the aerial robot depending on application


  • Civilian and Military applications
  • Scientific research
  • Search and Rescue
  • Surveillance
  • Monitoring
Last Updated: February 2024

Available for Licensing
TRL: 4


​Haijie Zhang
Jiefeng Sun
Jianguo Zhao

Reference Number
Licensing Manager

Aly Hoeher