Wei-Chih Wang | PubMed Health

PubMed2006

Transducing mechanical force by use of a diffraction grating sensor.

A novel means of transducing mechanical force by using a polymeric-based diffractive grating sensor is presented. The diffraction gratings are successfully fabricated upon poly(dimethyl siloxane) polymer substrates by holographic interference and micromolding. A micromaterial tensile test incorporated into the surface diffraction grating experiment showed that a relationship between the load and the observed diffraction-pattern shift could be obtained. The results show an excellent correlation between the optical measurement and load, with a sensitivity of 0.05 N.

Journal Article↗

PubMedDate not supplied

A shear and plantar pressure sensor based on fiber-optic bend loss.

Lower-limb complications associated with diabetes include the development of plantar ulcers that can lead to infection and subsequent amputation. While we know from force-plate analyses that medial/lateral and anterior/posterior shear components of ground-reaction forces exist, little is known about the actual distribution of these stresses during daily activities or about the role that shear stresses play in causing plantar ulceration. Furthermore, one critical reason why these data have not been obtained previously is the lack of a validated, widely used, commercially available shear sensor, partly because of the various technical issues associated with measuring shear. In this study, we present a novel means of transducing plantar pressure and shear stress with a fiber-optic sensor. The pressure/shear sensor consists of an array of optical fibers lying in perpendicular rows and columns separated by elastomeric pads. We constructed a map of normal and shear stresses based on observed macrobending through the intensity attenuation from the physical deformation of two adjacent perpendicular fibers. Initial results show that this sensor exhibits low noise and responds to applied normal and shear loads with good repeatability.

Biomechanical Phenomena↗