Toward the implementation of exible sensing sheet with bre Bragg grating sensing elements

Optical sensing sheets, based on Fibre Bragg Grating (FBG) sensing elements embedded in exible polydimethylsiloxane (PDMS), are produced and tested. The device shows promise in pressure mapping and tactile applications, in elds such as robotics and rehabilitation. FBGs inscribed in highly-birefringent photonic crystal bres, reecting two Bragg peaks, are used, and the potential to discriminate pressure and temperature is explored. The prototypes were produced by moulding technology and PDMS was cured at room temperature. One sample with FBGs embedded in the middle layer of a 2 mm thick PDMS sheet exhibited a linear pressure sensitivity of about 2:6 pm/kPa over the range of 0 250 kPa. Another sample was proposed and tested for temperature insensitive measurements, by realising local stress concentration at FBG sections of the embedded bre.