On Robotic Manipulation of Flexible Flat Cables: Employing a Multi-Modal Gripper with Dexterous Tips, Active Nails, and a Reconfigurable Suction Cup Module Joao Buzzatto, Jayden Chapman, Mojtaba Shahmohammadi, Felipe Sanches, Mahla Nejati, Saori Matsunaga, Rintaro Haraguchi, Toshisada Mariyama, Bruce MacDonald, and Minas Liarokapis Abstract— A popular solution for connecting different com- ponents in modern electronics, such as mobile phones, laptops, tablets, etc, is the use of flexible flat cables (FFC). Typically, it takes hours of repetition from a highly trained worker, or a high precision autonomous robot with specialised end effectors to reliably manage the installation of these cables. Human workers are prone to error, and cannot work endlessly without a break, while the robots often come with a significant expense, and require a substantial amount of time to program and repro- gram. Additionally, the use of sophisticated sensing elements further increases the complexity of the required control system. As a result, the performance and robustness of such systems is far from sufficient, hindering their mass adoption. The manipulation of FFCs is also quite challenging. In this work, we focus on the robotic manipulation of a plethora of flexible cables, proposing a multi-modal gripper with locally-dexterous tips and active fingernails. The fingers of the gripper are equipped with: i) locally-dexterous fingertips that accommodate manipulation-capable degrees of freedom, ii) a combination of Nitinol-based active fingernails and suction cups that allow picking up and handling of cables that rest on flat surfaces, and iii) compliant finger-pads that conform to the object surface to increase grasping stability. The proposed robotic gripper is equipped with a camera and a perception system that allow for the execution of complex cable manipulation and assembly tasks in dynamic environments. I. I NTRODUCTION Flexible cables such as those belonging in the class of Flexible Flat Cables (FFC) have become increasingly popular in the electronics industry, and are used for connecting a wide range of electronic components in consumer devices (e.g., smartphones, laptops, tables etc.). The handling and assembly of such cables typically relies on highly trained workers that are called to perform repetitive tasks in factory settings, or on simple robotic devices that are equipped Joao Buzzatto, Jayden Chapman, Mojtaba Shahmohammadi, Felipe Sanches, and Minas Liarokapis are with the New Dexterity research group, Department of Mechanical and Mechatronics Engineering, The Univer- sity of Auckland, New Zealand. E-mails: {jsan819, jcha855, msha851, fsan668}@aucklanduni.ac.nz, minas.liarokapis@auckland.ac.nz Mahla Nejati and Bruce MacDonald are with the Centre for Automation and Robotic Engineering Science, Department of Electrical, Computer and Software Engineering, The University of Auckland, New Zealand. E-mail: b.macdonald@auckland.ac.nz Saori Matsunaga, and Toshisada Mariyama are with the Information Technology R&D Center, Mitsubishi Electric Corporation, Japan. Emails: matsunaga.saori@dc.mitsubishielectric.co.jp, mariyama.toshisada@ab.mitsubishielectric.co.jp. Rintaro Haraguchi is with the Advanced Technology R&D Center, Mitsubishi Electric Corporation, Japan. Email: Haraguchi.Rintaro@dc.mitsubishielectric.co.jp. Fig. 1. The developed multi-modal robot gripper is equipped with a reconfigurable suction cup module that enables grasping of cables from flat surfaces without compromising the ability of the gripper to grasp other objects, dexterous tips that can manipulate the cables within the gripper, and active Shape Memory Alloy based fingernails that can be used to pick up objects from flat surfaces as well as for micromanipulation. The base of the proposed robotic gripper accommodates a camera that facilitates detection and pose estimation of flexible flat cables. with clamping structures and/or on suction cups. But human workers get distracted, tired, and need breaks, while the rigid, simplistic robotic end-effectors lack the required dexterity to execute complex robotic manipulation tasks. Traditional end-effectors are also difficult to program, and they rely on sophisticated sensing and complicated control laws to avoid damaging the handled cables [1]. Over the last decades, a new class of adaptive/compliant, underactuated, tendon and linkage driven robot grippers and hands has been proposed. The introduction of struc- tural compliance into the fingers structure has become a popular solution for increasing stability and efficiency of the execution of grasping and dexterous manipulation tasks even under object pose uncertainties without increasing the control and operation complexity, all while maintaining a