Skinflow: A soft robotic skin based on fluidic transmission

In this paper we present Skinflow, a novel soft robotic sensor based on liquid transmission. The sensor combines liquid filled soft silicone chambers and optical sensors to measure pressure, bending and vibration. When mechanically stimulated, the volume of the chambers changes and this change is transmitted to a display cell by an incompressible, coloured liquid. The displacement of the liquid in the channels is captured by a CCD camera and is quantified by image processing algorithms. We present three implementations of this concept. The first device is a soft button array with four pressure sensitive buttons. The second implementation is a three-dimensional soft touchpad, that consists of two sensor layers oriented at 90° to each other. Both layers have eight macrochannels that are filled with coloured liquid. The sensor is able to measure the position and the intensity of the touch. Finally, the third device shows how the processing unit for the proposed liquid filled sensors can be integrated using a smart vision camera and a microcontroller. Three soft bend sensors are connected to the processing unit and we control the brightness of three light emitting diodes (LEDs) in realtime by bending them. The presented sensors are safe, low cost and scalable. They can be used in soft robots, smart homes and wearables as well as for medical diagnosis, especially where electronic devices cannot be used due to electromagnetic interference (e.g. magnetic resonance imaging).

[1]  Iain A. Anderson,et al.  A numerical method for measuring capacitive soft sensors through one channel , 2018 .

[2]  Michael Thomas Tolley,et al.  3D printed resistive soft sensors , 2018, 2018 IEEE International Conference on Soft Robotics (RoboSoft).

[3]  Yong He,et al.  Three-Dimensional Printed Wearable Sensors with Liquid Metals for Detecting the Pose of Snakelike Soft Robots. , 2018, ACS applied materials & interfaces.

[4]  Daniel M. Vogt,et al.  Batch Fabrication of Customizable Silicone‐Textile Composite Capacitive Strain Sensors for Human Motion Tracking , 2017 .

[5]  Jonathan Rossiter,et al.  The TacTip Family: Soft Optical Tactile Sensors with 3D-Printed Biomimetic Morphologies , 2018, Soft robotics.

[6]  R. Hornfeck,et al.  A Novel Bio-Inspired Fluidic Actuator for Robotic Applications , 2014 .

[7]  Charlie C. L. Wang,et al.  Color-Based Sensing of Bending Deformation on Soft Robots , 2018, 2018 IEEE International Conference on Robotics and Automation (ICRA).

[8]  Jonathan Rossiter,et al.  Development of a tactile sensor based on biologically inspired edge encoding , 2009, 2009 International Conference on Advanced Robotics.

[9]  Isao Shimoyama,et al.  Stretchable liquid tactile sensor for robot-joints , 2010, 2010 IEEE International Conference on Robotics and Automation.

[10]  Yiwei Tao,et al.  Wearable soft artificial skin for hand motion detection with embedded microfluidic strain sensing , 2015, 2015 IEEE International Conference on Robotics and Automation (ICRA).

[11]  O. Brand,et al.  All-soft sensing platform based on liquid metal for liquid- and gas-phase VOC detection , 2016, 2016 IEEE SENSORS.

[12]  Erik H. Skorina,et al.  Toward Modular Soft Robotics: Proprioceptive Curvature Sensing and Sliding-Mode Control of Soft Bidirectional Bending Modules. , 2017, Soft robotics.

[13]  Yong-Lae Park,et al.  Highly stretchable optical sensors for pressure, strain, and curvature measurement , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[14]  Yong-Lae Park,et al.  Design and Fabrication of Soft Artificial Skin Using Embedded Microchannels and Liquid Conductors , 2012, IEEE Sensors Journal.

[15]  O. Brand,et al.  Multiscale and Uniform Liquid Metal Thin‐Film Patterning Based on Soft Lithography for 3D Heterogeneous Integrated Soft Microsystems: Additive Stamping and Subtractive Reverse Stamping , 2018 .

[16]  Yong-Lae Park,et al.  Fiber optically sensorized multi-fingered robotic hand , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[17]  Jonathan Rossiter,et al.  TACTIP - Tactile Fingertip Device, Texture Analysis through Optical Tracking of Skin Features , 2013, Living Machines.

[18]  Helmut Hauser,et al.  MultiTip: A multimodal mechano-thermal soft fingertip , 2018, 2018 IEEE International Conference on Soft Robotics (RoboSoft).

[19]  Jonathan Rossiter,et al.  Proprioceptive Flexible Fluidic Actuators Using Conductive Working Fluids , 2017, Soft robotics.