Micromachined Tactile Sensor for Soft-Tissue Compliance Detection

Compliance detection becomes very essential in minimally invasive surgery (MIS). It can help in detection of cancerous lumps and/or for deciding on tissue healthiness. In this paper, a micromachined piezoresistive tactile sensor, with two serpentine springs and 500-μm cubic mesas, has been designed for detecting the compliance of soft tissue independent of the applied distance between the sensor and the tissue. The measuring range of the sensor is chosen to be associated with the soft-tissue properties. The sensor parameters are optimized to give high sensitivity and linearity of the sensor output. The design is simulated using ANSYS for checking the sensor performance. Then, the sensor is fabricated and tested by three types of specimens, namely, specimen chips with known stiffness, silicone rubber specimens, and chicken organ specimens (leg and heart). For the specimen chips and silicone rubber specimens, the sensor distinguished between different stiffnesses independent of the applied displacement in the range of 50-200 μm. The sensor measured Young's modulus up to 808 kPa with an average error of ±7.25%. For the chicken leg and heart, the sensor distinguished between them under the applied displacement from 100 to 200 μm, and they were calculated as 12 ±1 kPa and 81 ±8 kPa, respectively.

[1]  W. Hayes,et al.  A mathematical analysis for indentation tests of articular cartilage. , 1972, Journal of biomechanics.

[2]  Sadao Omata,et al.  Fabrication of micro tactile sensor for the measurement of micro-scale local elasticity , 2004 .

[3]  Mitsuhiro Shikida,et al.  Active tactile sensor for detecting contact force and hardness of an object , 2003 .

[4]  Nadim Maluf,et al.  An Introduction to Microelectromechanical Systems Engineering , 2000 .

[5]  A F Mak,et al.  Estimating the effective Young's modulus of soft tissues from indentation tests--nonlinear finite element analysis of effects of friction and large deformation. , 1997, Medical engineering & physics.

[6]  A. Erdman,et al.  Flexible Tactile Sensor for Tissue Elasticity Measurements , 2009, Journal of Microelectromechanical Systems.

[7]  J. R. Hewit,et al.  Tactile sensing technology for minimal access surgery––a review , 2003 .

[8]  Toshiyuki Tsuchiya,et al.  Design and Simulation of a Tactile Sensor for Soft-Tissue Compliance Detection , 2008 .

[9]  Osamu Tabata,et al.  Tactile sensor for compliance detection , 2007 .

[10]  Sadao Omata,et al.  New tactile sensor like the human hand and its applications , 1992 .

[11]  M. Shikida,et al.  Multifunctional active tactile sensor using magnetic micro actuator , 2005, 18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005..

[12]  Javad Dargahi,et al.  Sensitivity analysis of a novel tactile probe for measurement of tissue softness with applications in biomedical robotics , 2007 .

[13]  Javad Dargahi,et al.  Design and modeling of an endoscopic piezoelectric tactile sensor , 2005 .

[14]  Jan Wikander,et al.  Tactile sensing in intelligent robotic manipulation - a review , 2005, Ind. Robot.

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

[16]  Y. Murayama,et al.  Considerations in the design and sensitivity optimization of the micro tactile sensor , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.