The study reported here shows that PDMS polymer resonators can be tuned using an external electric field. The studies also show the potential for high-resolution electric field sensors and non-contact displacement sensors. The sensitivity of the microsphere to an applied external electric field can be improved if the microsphere is poled in an external electric field. In addition, if the polymer microsphere is doped with magnetic polarizable particle, it can be tuned using an external magnetic field, and could potentially be used as a magnetic field sensor. The data reported here show a sensor resolution of the order of mT using a microresonator with optical quality factor of 107. This resolution could be improved using softer polymers and magnetic polarizable particles with larger magnetic permeability.

Chapter Contents:

• 7.1 Sensor concept
• 7.1.1 Tethered sensors
• 7.1.2 Untethered sensors
• 7.2 Stress and strain tuning of an optical spherical resonator
• 7.3 Electric field induced WGMs
• 7.4 Magnetic field induced WGM
• 7.5 Conclusions
• References

Inspec keywords: whispering gallery modes; micromechanical resonators; magnetic particles; optical sensors; magnetic field measurement; optical resonators; displacement measurement; magnetic sensors; electric field measurement; microsensors; electric sensing devices; optical polymers

Other keywords: electric field sensors; polymer microsphere; magnetic polarizable particle; optical quality factor; microresonator; magnetic permeability; PDMS polymer resonators; noncontact displacement sensors; magnetic field sensor; whispering gallery mode spherical resonators

Subjects: Optical polymers and other organic optical materials; Magnetic materials; Spatial variables measurement; Sensing and detecting devices; Voltage measurement; Waveguide and microwave transmission line components; Measurement of basic electric and magnetic variables; Micromechanical and nanomechanical devices and systems; MEMS and NEMS device technology; Spatial variables measurement; Magnetic variables measurement; Optical materials; Microsensors and nanosensors