When I first joined the CEI Lab as an undergrad, I worked on a few different projects. For example, I assembled one of the early versions of a robot studying granular media[1], and designed a large rack-and-pinion syringe pump for use in a soft shape-reconstruction sensor[2]. I started learning about Yoav Matia’s work on fluid-solid interactions, and began prototyping some of his ideas in the form of chained molded silicone chambers under his and Dr. Petersen’s guidance.

Once we had a good sense of how the real legs operated (like how fluids build hydrostatic pressure in lower cavities), we designed and assembled six functioning pneumatic legs using a flexible 3D-printed material, Sil-30, using a Carbon-3D printer. I also constructed a miniaturized syringe pump backpack to drive the pneumatic legs. The backpack was informed by my earlier rack-and-pinion pump used in the shape-reconstruction project, and I completed a working prototype of the hexapod for my M.Eng. in the winter of 2020.

Over the next six months or so, I was able to demonstrate untethered locomotion with the hexapod, and returned to campus to finish characterization of the real legs for use in Dr. Matia's simulated model. A paper detailing the physical model which characterized the legs as well as the robot was published in the winter of 2023. See Harnessing Nonuniform Pressure Distributions in Soft Robotic Actuators[3] for the full article! I’m extremely proud of this robot and was pleased to see it appear on a poster in the halls of the ECE department, as well as in an article from the Cornell Chronicle[4]!

References

1. Ma, D., Chen, J., Cutler, S., Petersen, K. (2024). Smarticle 2.0: Design of Scalable, Entangled Smart Matter. In: Bourgeois, J., et al. Distributed Autonomous Robotic Systems. DARS 2022. Springer Proceedings in Advanced Robotics, vol 28. Springer, Cham. https://doi.org/10.1007/978-3-031-51497-5_36

2. D. Ma, S. Ceron, G. Kaiser and K. Petersen, "Simple, Low-Cost Fabrication of Soft Sensors for Shape Reconstruction," in IEEE Robotics and Automation Letters, vol. 5, no. 3, pp. 4049-4054, July 2020, doi: 10.1109/LRA.2020.2986746.

3. Matia, Y., Kaiser, G.H., Shepherd, R.F., Gat, A.D., Lazarus, N. and Petersen, K.H. (2023), Harnessing Nonuniform Pressure Distributions in Soft Robotic Actuators. Adv. Intell. Syst., 5: 2200330. https://doi.org/10.1002/aisy.202200330

4. Nutt, David. “Soft Robots Harness Viscous Fluids for Complex Motions.” Cornell Chronicle, Cornell University, 23 Jan. 2023, news.cornell.edu/stories/2023/01/soft-robots-harness-viscous-fluids-complex-motions.