Flexible Shear Sensor Based on Embedded Optoelectronic Components

• Published in: IEEE photonics technology letters Vol. 23; no. 12; pp. 771 - 773
• Main Authors: Missinne, J, Bosman, E, Van Hoe, B, Van Steenberge, G, Kalathimekkad, S, Van Daele, P, Vanfleteren, J
• Format: Journal Article
• Language: English
• Published: IEEE 15-06-2011
• Subjects: Current measurement; Flexible; Force; optical; Optical sensors; Photodiodes; Robot sensing systems; Sensitivity; shear sensing; tactile sensing; Vertical cavity surface emitting lasers
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2011.2134844

Tactile shear stresses play an important role in the medical field and robotics. To monitor these stresses in situ, there is a need for unobtrusive flexible sensors that can be wrapped around curved surfaces or moving body parts. The presented sensor is based on changing coupling of optical power between a vertical-cavity surface-emitting laser (VCSEL) and a photodiode facing each other and separated by a deformable transducer layer. The required optoelectronic components were embedded in a polymer foil of only 40 μm thick, yielding a very thin and flexible total sensor stack of 250 μm thick. In the linear part of the range (between 2 and 5.5 N), the sensitivity of the prototype was -350 μA/N; the maximum measurable force was 5.5 N. However, by selecting the appropriate deformable sensor transducer material, the sensitivity and range can be tuned for a specific application.