Gravish·lab
Gravish
·
lab


The science & engineering of
dynamic & dexterous movement
Mechanical & Aerospace Engineering, UC San Diego
Flexible and compliant robotics

Flexibility and compliance can be beneficial for mobile robots that have to navigate unstrucured environments. Limbs and bodies that can bend in response to unexpected perturbations enable effective movement capabilities. We are developing new methods to fabricate flexible, compliant, or soft mobile robots using 3D printing and laser cutting.

Recent papers
  • Design of a Soft Everting Robot for Exploration in Granular Media. K Eken, N Gravish, M Tolley. IEEE RoboSoft. 2023.    (In Review).   
  • A reconfigurable soft linkage robot via internal virtual joints. M Jiang, J Wang, N Gravish. 2023.    (In Review).   
  • Scalable fluidic matrix circuits for controlling large arrays of individually addressable actuators. S Jadhav, P Glick, M Ishida, C Chan, I Abidnazari, J Shulze, N Gravish, M Tolley. Advanced Intelligent Systems. 2023.    (In Review).   
Selected videos
Collective Behavior

Running dynamics for small scale insects and robots are poorly understood. We explore legged movement at the small-scale by performing biomechanics experiments on high-speed running ants. We use micro-robotic models to test hypothesis of dynamic running in small scale systems.

Recent papers
  • Lateral contact yields longitudinal cohesion in active undulatory systems. W Zhou, J Dezha-Peralta, Z Hao, N Gravish. Physical Review E. 2022.    PDF:         LINK:         PREPRINT:        
  • Proprioceptive feedback design for gait synchronization in collective undulatory robots. Z Hao, W Zhou, N Gravish. Advanced Robotics. 2022.    PDF:         LINK:        
  • Collective synchronization of undulatory movement through contact. W Zhou, Hao, Z, N Gravish. Physical Review X. 2021.    PDF:         LINK:         PREPRINT:        
Selected videos
Legged locomotion

Running dynamics for small scale insects and robots are poorly understood. We explore legged movement at the small-scale by performing biomechanics experiments on high-speed running ants. We use micro-robotic models to test hypothesis of dynamic running in small scale systems.

Recent papers
  • The bumpy road ahead: The role of terrain roughness on animal walking, and where to go from here. G Clifton, A Stark, C Li, N Gravish. Journal of Experimental Biology. 2023.    (In Review).   
  • Flexoskeleton Limb Design For a Multi-functional Rolling and Crawling Robot. G Kim, N Gravish. IEEE RoboSoft. 2023.    (In Review).   
  • Directionally Compliant Legs Enable Crevasse Traversal in Small Ground-based Robots. E Lathrop, M Tolley, N Gravish. Advanced Intelligent Systems. 2023.    PDF:        
Selected videos
Flapping wing flight

Power efficiency of milli-scale robots can be improved through mechanical designs incorporating elastic structures for energy storage and recovery. Locomotion movements are often periodic (flapping wings, running gaits) and so actuation and power transmission through resonant systems could be beneficial. However, resonance and agility require conflicting modes of actuation: resonance favors actuation at a single frequency and agility favors actuation across a wide range of frequencies. We seek to resolve this conflict in locomotion efficiency and agility through novel mechanical design of compliant microrobots.

Recent papers
  • Structural damping renders the insect exoskeleton mechanically insensitive to non-sinusoidal deformations. E Wold, J Lynch, N Gravish, S Sponberg. J. Roy. Soc. Interface. 2023.    (In Review).    PREPRINT:        
  • Going against the flow: Bumblebees prefer to fly in headwinds, and display more variable body angles and ground speeds in tailwinds. S Combes, N Gravish, S Gagliardi. Journal of Experimental Biology. 2023.    (In Review).   
  • Soft Molds with Micro-Machined Internal Skeletons Improve Robustness of Flapping-Wing Robots. H Gao, J Lynch, N Gravish. Micromachines. 2022.    PDF:         LINK:        
Selected videos
Locomotion in granular media

Power efficiency of milli-scale robots can be improved through mechanical designs incorporating elastic structures for energy storage and recovery. Locomotion movements are often periodic (flapping wings, running gaits) and so actuation and power transmission through resonant systems could be beneficial. However, resonance and agility require conflicting modes of actuation: resonance favors actuation at a single frequency and agility favors actuation across a wide range of frequencies. We seek to resolve this conflict in locomotion efficiency and agility through novel mechanical design of compliant microrobots.

Recent papers
  • Design of a Soft Everting Robot for Exploration in Granular Media. K Eken, N Gravish, M Tolley. IEEE RoboSoft. 2023.    (In Review).   
  • Underactuated appendages enable sensing and swimming in granular environments. S Chopra, D Vasile, S Jadhav, M Tolley, N Gravish. Advanced Intelligent Systems. 2023.    (In Review).   
  • Anisotropic Forces for a Worm-Inspired Digging Robot. D Drotman, S Chopra, N Gravish, M Tolley. IEEE RoboSoft. 2022.    PDF:         LINK:        
Selected videos