New STIFF-FLOP module construction idea for improved actuation and sensing

Abstract

MRI compatibility, which often is a requirement for the new medical soft robot projects, greatly reduces available actuation methods and sensors. An example of such project is STIFF-FLOP, which aims to develop a soft silicone manipulator actuated by pressure. The current arm construction and method of actuation cause several undesirable effects, which pose problems for actuation and sensing. In this paper, the authors identify the source of those negative effects and propose improvements over the current construction to eliminate or limit their influence. The new construction concept is tested and compared with the current one. Possible ideas for further development are also proposed

Safe Testing of Electrical Diathermy Cutting Using a New Generation Soft Manipulator

“…1(c). The undesirable ballooning effect observed at higher pressures was initially restrained through an external sleeve [33], and was later substituted by internal braiding of the individual chambers to eliminate existing sensing and actuation issues [34]. In addition, the modules can be provided with a stiffening mechanism based on vacuum-actuated granular jamming [35], [36] of additional internal chambers filled with ground coffee granules, shown in Fig.…”

“…1(d). The design and fabrication processes of the modules are not a contribution of this paper and can be found with more detail in [28]- [34].…”

Tendon-Based Stiffening for a Pneumatically Actuated Soft Manipulator

“…The tendon-driven actuation mechanism is embedded into a single cylindrical silicone segment modelled after the STIFF-FLOP manipulator [10]. Figure 2 shows a side and cross-sectional view of the robot arm with the integrated antagonistic actuation principle.…”

“…It is noted that the created segment (Figure 2) has an inner free chamber of 9 mm diameter -this space is incorporated to pass through tubes from additional segments and wires when creating a manipulator with a series of multiple segements. A detailed description of the STIFF-FLOP manipulator can be found in [9], [10], [21].…”

“…The application of these types of robots can result in significant improvements within a number of fields where traditional robots are currently deployed [6]- [8]. One of these areas is Minimally Invasive Surgery (MIS) -also called laparoscopic or keyhole surgery [9], [10]. Most commonly, during minimally invasive procedures, rigid laparoscopic instruments are inserted Sideview and crosssection view of a segment of the STIFF-FLOP manipulator with integrated stiffening mechanism based on the antagonistic principle: three pairs of pneumatically actuated chambers are embedded into a silicone body and combined with three stretchable silicone tubes integrated inside the wall of the manipulator to guide tendons for stiffening.…”