Capacitive sensing of interfacial stresses

Studying interfacial stresses is an important step towards understanding load distributions in mechanical, biomedical, and industrial systems. This paper presents a capacitive sensor that is capable of simultaneously measuring compressive and shear stresses. The sensor consists of two electrode layers separated by a set of flexible and compressible polymer pillars. The sensor's response to compressive and shear stresses was tested and characterized up to 320 kPa and 70 kPa respectively. An algorithm to estimate the applied stresses based on sensor output was developed and validated. The applied compressive stresses were estimated with an accuracy of 95.04 % and shear stress with an accuracy of 89.45 %.

[1]  Joan E. Sanders,et al.  Measurement of stresses in three orthogonal directions at the residual limb-prosthetic socket interface , 1993 .

[2]  Ping Zhang,et al.  A full tactile sensing suite for dextrous robot hands and use in contact force control , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[3]  V. C. Roberts,et al.  Frictional action at lower limb/prosthetic socket interface. , 1996, Medical engineering & physics.

[4]  H. Morimura,et al.  A high-resolution capacitive fingerprint sensing scheme with charge-transfer technique and automatic contrast emphasis , 1999, 1999 Symposium on VLSI Circuits. Digest of Papers (IEEE Cat. No.99CH36326).

[5]  Mark Lee,et al.  Review Article Tactile sensing for mechatronics—a state of the art survey , 1999 .

[6]  Yaowu Mo,et al.  Micro-machined gas sensor array based on metal film micro-heater , 2001 .

[7]  K. Hosokawa,et al.  In-line pressure monitoring for microfluidic devices using a deformable diffraction grating , 2001, Technical Digest. MEMS 2001. 14th IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.01CH37090).

[8]  Jonathan Engel,et al.  Development of Polyimide-based Flexible Tactile Sensing Skin , 2002 .

[9]  Y. M. Shkel,et al.  Novel sensor technology for shear and normal strain detection with generalized electrostriction , 2002, Proceedings of IEEE Sensors.

[10]  Tracy L Beil,et al.  Interface pressures during ambulation using suction and vacuum-assisted prosthetic sockets. , 2002, Journal of rehabilitation research and development.

[11]  Joan E. Sanders,et al.  An explant model for the investigation of skin adaptation to mechanical stress , 2002, IEEE Transactions on Biomedical Engineering.

[12]  Roberto Guerrieri,et al.  A textile based capacitive pressure sensor , 2002, Proceedings of IEEE Sensors.

[13]  Tracy L Beil,et al.  Comparison of interface pressures with pin and suction suspension systems. , 2004, Journal of rehabilitation research and development.

[14]  James Cho Hong Goh,et al.  Comparative study between patellar-tendon-bearing and pressure cast prosthetic sockets. , 2004, Journal of rehabilitation research and development.

[15]  S G Zachariah,et al.  Changes in interface pressures and shear stresses over time on trans-tibial amputee subjects ambulating with prosthetic limbs: comparison of diurnal and six-month differences. , 2005, Journal of biomechanics.

[16]  J. E. Sanders,et al.  Interface mechanics in external prosthetics: review of interface stress measurement techniques , 1995, Medical and Biological Engineering and Computing.

[17]  J. Sanders,et al.  Effects of Fluid Insert Volume Changes on Socket Pressures and Shear Stresses: Case Studies from two Trans-Tibial Amputee Subjects , 2006, Prosthetics and orthotics international.

[18]  S. Marshall,et al.  Skin Problems in an Amputee Clinic , 2006, American journal of physical medicine & rehabilitation.

[19]  Analyses of prosthetic episodes in lower limb amputees , 2008, Prosthetics and orthotics international.

[20]  Pi-Cheng Tung,et al.  Data analysis using a combination of independent component analysis and empirical mode decomposition. , 2009, Physical review. E, Statistical, nonlinear, and soft matter physics.

[21]  Glenn K. Klute,et al.  Shear sensor for lower limb prosthetic applications , 2009, 2009 First Annual ORNL Biomedical Science & Engineering Conference.

[22]  Glenn K. Klute,et al.  Capacitive sensing of interfacial forces in prosthesis , 2010, 2010 IEEE International Workshop on Medical Measurements and Applications.