6.1Conclusions CONCLUSIONSANDFUTUREWORKS CHAPTER 6

CHAPTER

6

CONCLUSIONS AND FUTURE WORKS

6.1 Conclusions

It was presented the Soft Claw Gripper, a highly compliant bio-inspired instru-ment for handling delicate objects realized with an innovative design based on the embodied intelligence concept. A peculiarity of the SCG design is that dimensions could be easily scaled, so that it can become an industrial manipulator for han-dling of delicate object on the production line (for example in food industry), or also it can be used for micro-manipulation of electronic components. As a case of study, it has been specically adapted for the possible application in Minimally Invasive Surgery for manipulation of soft tissues, preventing and limiting the risk of causing damages. The philosophy at the base of this work is that this novel way of constructing tool could lead to simple, safe and competent end-eectors for mobile manipulation. A mathematical tool has been developed to optimize the design and to model the mechanical behavior of the system. The prototype has been manufactured following a four-steps fabrication procedure detailed described. Furthermore, it has been proposed the feasibility of structural modications to the standard prototype to improve specic capabilities. Through dierent gripper de-signs, various gripping actions can be engineered. By dierently incorporating cables into the soft gripper ngers, dierent gripping postures can be achieved. Such combinations of designs enable dierent robotic motions that mimic actions of soft body parts of octopus, brittle star or elephant. Furthermore, additional im-plementations, such as ngernails inclusion or surface nishing with smart layers could enrich the behavior menu of the robot of new capabilities, without interfer-ing with the desired compliant property. A benchmark for characterization has

6.2. Future Work Chapter 6. Conclusions and Future works been realized ad hoc, involving the developing of a custom sensing system, de-signed for the specic case of a soft instrument characterization. Together with the passively compliant palm, the exible ngers implement a perfect power grasp for spherical shapes but also cylindrical and hyperbolic shapes are well matched (Figure 6.1). This work has laid groundwork for the realization of a powerful

in-Figure 6.1: Spherical, cylindrical and complex grasping.

strument equipped with a kind of low-level intelligence sucient to ensure a safe but stable approach, without the need of a real force-feedback. The intertwined concepts of biomimicry, soft robotics and embodied intelligence have driven the designed of a bioinspired highly-compliant, under-actuated and scalable manipu-lator. This work has contributed to the eld of design for soft robotic MIS tools which could denitely bring advantages in manipulating soft tissue during tradi-tional or robotic-assisted laparoscopic procedure inside the insuated abdomen cavity.

6.2 Future Work

To trace back to the gripper ngertip force, we need a system calibration by means of FEM characterization of the balloon. From a known ngertip force the deformed state can be evaluated, hence, a point cloud can be calculated and then the volume of the deformed sphere. This will be carried out in the future work, together with the complete characterization in terms of ngertip exerted force. Afterwards, stability grasping test will be executed. The robotic arm will be used to disturb the grasping by means of known motion parameters to the end-eector and using a load cell, interposed between the robotic arm wrist and the gripper, will be detected the maximum resistance force without slipping.

6.2. Future Work Chapter 6. Conclusions and Future works This thesis aims to be only a preliminary work in designing and developing a soft robotics tool for MIS. In the future will be evaluated eectively its real usefulness in the surgical eld through appropriate testing procedures.

To increase the dexterity of the manipulator for precision grasp, it will be studied the possibility of changing the relative position of two of the ngers.

To transform the SCG in a complete mechatronic system, it is needed to provide the appropriate and compatible technology features. Indeed, electronics embedded in a soft robot must be suciently small or elastic in order to preserve the natural mechanics of the host. The promising research in elastically soft and stretchable electronics will denitely bring benet to soft robotic smart instruments. These electronics are composed of soft silicone rubber embedded with microuidic chan-nels of liquid-phase Gallium-Indium (GaIn) alloy. Because the GaIn alloy is liquid at room temperature, it remains intact and conductive as the surrounding elas-tomer is deformed during stretching, compression, or shearing. Soft sensors could be integrated without altering the compliant mechanical property to measure pres-sure at the ngertip and deformation(for example to achieve shape recognition). Regarding implementations, will be evaluated the possibility to engineering also the palm, which is left inert in this preliminary work, with an articial suction cup on the palm to increase the adhesion capability during a grasping, as the suckers covering the ventral side of octopus tentacles do [Follador et al., 2013], or else the possibility to exploit the jamming of granular material to coat the ngers and palm [Brown et al., 2010].

It could also be interesting to explore the feasibility of shape recognition of grasped objects, employing the passive deformation of the material, by measure deection on the front-side of the nger through embedded sensors. Bending and pressure sensors could be selected for receiving feedback by the environment through the material itself.

6.2. Future Work Chapter 6. Conclusions and Future works