Covering a Robot Fingertip With uSkin: A Soft Electronic Skin With Distributed 3-Axis Force Sensitive Elements for Robot Hands

Abstract

Distributed tactile sensing is crucial to perform stable, subtle, and precise manipulation so that a robot can recognize and handle objects properly. However, currently existing skin sensors still have common problems such as complex and expensive production or are difficult to integrate into robot hands. In particular, a practical distributed soft skin sensor system that can cover various parts of the robot hand, measure force in 3axis, with a subcentimeter spatial density, and digital output at the same time does not exist yet. This paper discusses uSkin, a soft, distributed, 3-axis force sensor for robot hands and presents its implementation for multi-curved fingertips. The sensor is lowcost, easy to manufacture, and can measure normal and shear forces. The experimental results revealed that this sensor has 10% hysteresis for perpendicular force with a maximum range of 6 N. The Signal to Noise Ratio (SNR) value of 54 dB for 0.4 N load was achieved, which constitutes the state of the art for this kind of sensors. Evaluation experiments also showed that the distributed 3-axis load cells could produce vectors that represent the shape of objects. This opens the possibility that the sensor can be used for classifying different shapes. Furthermore, the fingertip sensor was installed on the Allegro hand and the changing force measurements when the robot is grasping an object are presented.

Deep Visuo-Tactile Learning: Estimation of Tactile Properties from Images

“…A. Hardware Setup 1) Tactile sensor: The uSkin tactile sensor we use [13], [14] consists of 16 taxels in a 4 × 4 square formation and is capable of measuring applied pressing forces and shear force in the x, y, and z axes as well as temperature ( Fig. 3(a) shows the coordinate system of the tactile sensor).…”

An Embedded, Multi-Modal Sensor System for Scalable Robotic and Prosthetic Hand Fingers

“…Tomo et al [9,10] use commercially available digital three-axis Hall effect sensors together with a magnet embedded into flexible material above the sensor to measure normal and shear forces through the displacement of the magnet. These modular sensors were integrated into the Allegro [11] and the iCub hands and fingers [12,13]. An interesting variation of this sensing method is presented in [14], where a single sensor is used to measure elastic deformation of the finger structure induced by applied forces.…”

Graphene Oxide Films Prepared Using Gelatin Nanofibers as Wearable Sensors for Monitoring Cardiovascular Health

“…Wearable electronic skins (e‐skins) are emerging devices being developed by scientists globally, and explored for applications in biosensing, diagnosing diseases, monitoring health status, detecting emotion, robots, etc. When e‐skins are attached on the human skin, animals, or plants surfaces, environmental or specimen physiological information will be captured and converted into electronic signals.…”