Sensing & Manipulation

Soft manipulation and sensing is a multidisciplinary field that draws inspiration from living organisms to create robots with flexible, adaptable structures. These robots mimic the compliant nature of natural tissues, human muscles, and plant-like movements, making them ideal for tasks requiring safe interaction, delicate manipulation, and adaptability. They use compliant materials to mitigate risks when working in close proximity to humans or handling fragile objects, making them suitable for applications such as minimally invasive surgery in healthcare. Soft sensors integrated into the robot's body provide real-time feedback on its interactions with the environment, enabling precise control and manipulation. This combination of soft manipulation and sensing extends the applicability of soft robotics to various industries, fostering innovation and scientific advancement.

SIMBA: A Soft Continuum Manipulator

In this paper, we present a novel hybrid design for a modular continuum arm with independent actuation. Our work includes detailed arm design, kinematic and static modeling, and module characterization. This approach combines soft and hard materials in hybrid structures and hybrid joints, allowing for both continuum bending and traditional joint-based motion. The rectangular planar springs provide exceptional passive stiffness, making it suitable for unstructured manipulation tasks. The modular module design features parallel planar springs with independent actuation. We found a positional error of approximately 3.4%, a bending force requirement of up to 3.13 N, and a lateral load capacity of 11 N without actuation. The static model suggests challenges in predicting bending force after 65 mm of deflection. This modular and versatile arm design has applications in service robotics, pipe maintenance, and nuclear tasks, offering ease of fabrication and maintenance.

1. Mishra, A.K., Mondini, A., Del Dottore, E., Sadeghi, A., Tramacere, F. and Mazzolai, B., 2018. Modular Continuum Manipulator: Analysis and Characterization of Its Basic Module. Biomimetics, 3(1), p.3. https://doi.org/10.3390/biomimetics3010003 14.

2.Mishra, A.K., Del Dottore, E., Sadeghi, A., Mondini, A. and Mazzolai, B., 2017. SIMBA: Tendon-Driven Modular continuum arm with the soft reconfigurable gripper. Frontiers in Robotics and A.I., 4, p.4. https://doi.org/10.3389/frobt.2017.00004

Simplified Sensing and Control of a Plant-Inspired Cable Driven Manipulator

Navigating complex, unstructured environments is a persistent challenge in robotics. Learning from plants, such as climbing vines, offers potential solutions. These plants, with their flexible structures, excel at adapting and utilizing their surroundings for efficient movement. Likewise, continuum robots, known for their versatility but complex mechanics, face control challenges, especially in manipulation and inspections. This study introduces a novel approach to detect potential support structures for vine-inspired continuum arms. Unlike conventional methods, our approach uses simplified control and sensor arrays to detect contact occurrences. We calculate contact point positions using a kinematic model. While our results are preliminary, they hold promise for adaptive exploration strategies and lay the groundwork for vine-inspired robots capable of coiling around support structures.

1.  Visentin F.*, Mishra A.K.*, Naselli G.A.*, Mazzolai B., Simplified Sensing and Control of a Plant-Inspired Cable-Driven Manipulator, IEEE Robosoft conference (2019), South Korea. https://doi.org/10.1109/ROBOSOFT.2019.8722729

SurgGrip: A Compliant 3D Printed Gripper for Vision-based Grasping

This paper presents the SurgGrip, a 3D-printed gripper designed for automated handling of flat surgical instruments. It features compliant, flat fingertips with mortise and tenon joints, soft pads for stable instrument grasping, and a four-bar linkage with a lead screw for precise finger movement. The SurgGrip combines soft and rigid components through a hybrid approach, offering passive compliance through linear and torsional springs. It enables automated manipulation of surgical tools using vision-based control, making it suitable for various applications in the medical field.

1. Kim, J*., Mishra, A.K.*, Radi, L., Bashir, M.Z., Nocentini, O. and Cavallo, F., 2022. SurgGrip: a compliant 3D printed gripper for vision-based grasping of surgical thin instruments. Meccanica, pp.1-16. https://doi.org/10.1007/s11012-022-01594-6

Optical Waveguide Sensor 

Optical waveguide touch sensing represents a cutting-edge technology with significant potential in the field of soft robotics. This innovative approach leverages the principles of optical waveguides to enable highly sensitive and versatile tactile sensing in soft robotic systems. By integrating these waveguides into the robot's structure, it can detect and respond to touch and pressure with exceptional precision. The advantages of this technology lie in its ability to provide real-time feedback on the robot's interactions with its environment, enhancing safety and control. Furthermore, optical waveguide touch sensing is non-intrusive and can be seamlessly integrated into various soft robot designs, making it a promising tool for advancing the capabilities of these flexible and adaptable machines in applications ranging from healthcare to human-robot interaction.

1. Jo, J., Xu, A., Mishra, A.K., Bai, H., Derkevorkian, A., Rabinovitch, J., Park, H. and Shepherd, R.F., 2022. Measurement of Parachute Canopy Textile Deformation Using Mechanically Invisible Stretchable Lightguides. Advanced Materials Technologies, p.2200437. https://doi.org/10.1002/admt.202200437

2. Xu, P.A., Mishra, A.K., Bai, H., Aubin, C.A., Zullo, L. and Shepherd, R.F., 2019. Optical lace for synthetic afferent neural networks. Science Robotics, 4(34). https://doi.org/10.1126/scirobotics.aaw6304