Hybrid Robotic Platform
Project Objectives
Design robotic platforms that utilize soft actuation or active materials.
Fabricate the robotic platform.
Fabricate liquid dielectric based actuators for use on the robotic platforms.
Methodology and results
A robotic platform was designed that mimics the locomotion of a snake.
The main focus of the development has centered around electrohydraulic soft actuators [1-3]. That act on the principles of electrostatic and hydraulic actuation.
A liquid dielectric sits between two compliant electrodes, contained by a flexible polymer shell.
The electrodes and film gradually collapse toward each other from one corner of the electrode to the other [1],[5].
When the electrodes and film close together, a majority of the fluid is pushed into the area not covered by an electrode.
A thin layer of the liquid dielectric remains between the electrode [4].
The actuators will be stacked to cause large displacement, and move the linkages.
The chassis of this platform uses purely additively manufactured linkages.
The actuators require high voltages (~4.5 kV to begin activation, ~10 kV for full activation), so a on-board DC-HVDC transformer will be used to supply the actuators.
The compact and lightweight Arduino UNO will be used as the controller. The microcontroller will produce a DC voltage (maximum 5V) and the DC-HVDC transformer will step the voltage up (maximum 5kV).
References
[1] P. Brenner, Michael & H. Lang, Jeffrey & Li, Jian & Slocum, Alexander. (2004). Optimum Design of an Electrostatic Zipper Actuator. 2004 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2004. 2.
[2] Acome, E., Mitchell, S. K., Morrissey, T. G., Emmett, M. B., Benjamin, C., King, M., … Keplinger, C. (2018). Hydraulically amplified self-healing electrostatic actuators with muscle-like performance. Science, 359(6371), 61–65. https://doi.org/10.1126/science.aao6139
[3] Kellaris, N., Venkata, V. G., Smith, G. M., Mitchell, S. K., & Keplinger, C. (2018). Peano-HASEL actuators: Muscle-mimetic, electrohydraulic transducers that linearly contract on activation. Science Robotics, 3(14), 1–11. https://doi.org/10.1126/scirobotics.aar3276
[4] Park, T., & Cha, Y. (2019). Soft gripper actuated by electro-hydraulic force. (March), 46. https://doi.org/10.1117/12.2514008
[5] Kellaris, N., Venkata, V. G., Rothemund, P., & Keplinger, C. (2019). An analytical model for the design of Peano-HASEL actuators with drastically improved performance. Extreme Mechanics Letters, 29, 100449. https://doi.org/10.1016/j.eml.2019.100449