Design and Fabrication of Soft Artificial Skin Using Embedded Microchannels and Liquid Conductors

We describe the design, fabrication, and calibration of a highly compliant artificial skin sensor. The sensor consists of multilayered mircochannels in an elastomer matrix filled with a conductive liquid, capable of detecting multiaxis strains and contact pressure. A novel manufacturing method comprised of layered molding and casting processes is demonstrated to fabricate the multilayered soft sensor circuit. Silicone rubber layers with channel patterns, cast with 3-D printed molds, are bonded to create embedded microchannels, and a conductive liquid is injected into the microchannels. The channel dimensions are 200 μm (width) × 300 μm (height). The size of the sensor is 25 mm × 25 mm, and the thickness is approximately 3.5 mm. The prototype is tested with a materials tester and showed linearity in strain sensing and nonlinearity in pressure sensing. The sensor signal is repeatable in both cases. The characteristic modulus of the skin prototype is approximately 63 kPa. The sensor is functional up to strains of approximately 250%.

[1]  Whitney Rj The measurement of changes in human limb-volume by means of a mercury-inrubber strain gauge. , 1949 .

[2]  R. J. Whitney,et al.  The measurement of volume changes in human limbs , 1953, The Journal of physiology.

[3]  G. Whitesides,et al.  Soft Lithography. , 1998, Angewandte Chemie.

[4]  G. Whitesides,et al.  Rapid Prototyping of Microfluidic Systems in Poly(dimethylsiloxane). , 1998, Analytical chemistry.

[5]  Multi-component force sensor based on multiplexed fibre Bragg grating strain sensors , 2001 .

[6]  P. C. Paris,et al.  The Stress Analysis of Cracks Handbook, Third Edition , 2000 .

[7]  Hiroshi Tada,et al.  The stress analysis of cracks handbook , 2000 .

[8]  V. Lumelsky,et al.  Sensitive skin , 2000, IEEE Sensors Journal.

[9]  Allison M. Okamura,et al.  Feature Detection for Haptic Exploration with Robotic Fingers , 2001, Int. J. Robotics Res..

[10]  Takashi Maeno,et al.  Artificial finger skin having ridges and distributed tactile sensors used for grasp force control , 2001, Proceedings 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems. Expanding the Societal Role of Robotics in the the Next Millennium (Cat. No.01CH37180).

[11]  Masayuki Inaba,et al.  Development of soft and distributed tactile sensors and the application to a humanoid robot , 2002, Adv. Robotics.

[12]  Zamora,et al.  Electronic textiles: a platform for pervasive computing , 2003, Proceedings of the IEEE.

[13]  Clayton C. Bohn,et al.  Direct Strain Measurement of Polypyrrole Actuators Controlled by the Polymer/Gold Interface , 2003 .

[14]  M. Asada,et al.  Sensing Ability of Anthropomorphic Fingertip with Multi-Modal Sensors , 2003 .

[15]  Hugh M. Herr,et al.  New horizons for orthotic and prosthetic technology: artificial muscle for ambulation , 2004, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[16]  Shuichi Wakimoto,et al.  Development of intelligent McKibben actuator , 2005, 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[17]  P. Dario,et al.  Characterization of a novel hybrid silicon three-axial force sensor , 2005 .

[18]  T. Sakurai,et al.  Cut-and-paste customization of organic FET integrated circuit and its application to electronic artificial skin , 2005, IEEE Journal of Solid-State Circuits.

[19]  J. Engel,et al.  Polymer micromachined multimodal tactile sensors , 2005 .

[20]  E. Scilingo,et al.  Strain sensing fabric for hand posture and gesture monitoring. , 2005, IEEE transactions on information technology in biomedicine : a publication of the IEEE Engineering in Medicine and Biology Society.

[21]  Mark R. Cutkosky,et al.  Force Sensing Robot Fingers using Embedded Fiber Bragg Grating Sensors and Shape Deposition Manufacturing , 2007, Proceedings 2007 IEEE International Conference on Robotics and Automation.

[22]  Dong Sung Kim,et al.  Fabrication of microchannel containing nanopillar arrays using micromachined AAO (anodic aluminum oxide) mold , 2007 .

[23]  Gamini Dissanayake,et al.  Capacitive sensor for object ranging and material type identification , 2008 .

[24]  L.D. Seneviratne,et al.  State-of-the-Art in Force and Tactile Sensing for Minimally Invasive Surgery , 2008, IEEE Sensors Journal.

[25]  Chen Chao,et al.  A novel fluidic strain sensor for large strain measurement , 2008 .

[26]  G. Whitesides,et al.  Eutectic Gallium‐Indium (EGaIn): A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature , 2008 .

[27]  Veronica J. Santos,et al.  Biomimetic Tactile Sensor Array , 2008, Adv. Robotics.

[28]  Mark R. Cutkosky,et al.  Exoskeletal Force-Sensing End-Effectors With Embedded Optical Fiber-Bragg-Grating Sensors , 2009, IEEE Transactions on Robotics.

[29]  Paolo Dario,et al.  Development of a stretchable skin-like tactile sensor based on polymeric composites , 2009, 2009 IEEE International Conference on Robotics and Biomimetics (ROBIO).

[30]  Tsukasa Ogasawara,et al.  Flexible Sensor for McKibben Pneumatic Artificial Muscle Actuator , 2009, Int. J. Autom. Technol..

[31]  Russell H. Taylor,et al.  A sub-millimetric, 0.25 mN resolution fully integrated fiber-optic force-sensing tool for retinal microsurgery , 2009, International Journal of Computer Assisted Radiology and Surgery.

[32]  Maryanne C. J. Large,et al.  The role of viscoelastic properties in strain testing using microstructured polymer optical fibres (mPOF) , 2009 .

[33]  Tsukasa Ogasawara,et al.  Flexible sensor for Mckibben pneumatic actuator , 2009, 2009 IEEE Sensors.

[34]  Mark R. Cutkosky,et al.  A robust, low-cost and low-noise artificial skin for human-friendly robots , 2010, 2010 IEEE International Conference on Robotics and Automation.

[35]  Oussama Khatib,et al.  Design and Control of a Bio-inspired Human-friendly Robot , 2010 .

[36]  Rebecca K. Kramer,et al.  Hyperelastic pressure sensing with a liquid-embedded elastomer , 2010 .

[37]  R. J. Black,et al.  Real-Time Estimation of 3-D Needle Shape and Deflection for MRI-Guided Interventions , 2010, IEEE/ASME Transactions on Mechatronics.

[38]  Andrew G. Gillies,et al.  Nanowire active-matrix circuitry for low-voltage macroscale artificial skin. , 2010, Nature materials.

[39]  John T W Yeow,et al.  Conductive polymer-based sensors for biomedical applications. , 2011, Biosensors & bioelectronics.

[40]  Robert J. Wood,et al.  Wearable tactile keypad with stretchable artificial skin , 2011, 2011 IEEE International Conference on Robotics and Automation.

[41]  Robert J. Wood,et al.  Soft curvature sensors for joint angle proprioception , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[42]  Robert J. Wood,et al.  Stretchable circuits and sensors for robotic origami , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[43]  Robert J. Wood,et al.  Bio-inspired active soft orthotic device for ankle foot pathologies , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[44]  R. Wood,et al.  A non-differential elastomer curvature sensor for softer-than-skin electronics , 2011 .

[45]  Robert J. Wood,et al.  Soft artificial skin with multi-modal sensing capability using embedded liquid conductors , 2011, 2011 IEEE SENSORS Proceedings.

[46]  Robert J. Wood,et al.  Applicability of Shape Memory Alloy Wire for an Active, Soft Orthotic , 2011, Journal of Materials Engineering and Performance.

[47]  Oussama Khatib,et al.  Capacitive skin sensors for robot impact monitoring , 2011, 2011 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[48]  C.-M. Tsao,et al.  The development of a highly twistable tactile sensing array with stretchable helical electrodes , 2011 .

[49]  K. Peters Polymer optical fiber sensors—a review , 2010 .