Bone-Integrated Optical Microlasers for In-Vivo Diagnostic Biomechanical Performances

Abstract

Bones experience mechanical loads on a daily basis. It is difficult to obtain biomechanical performances in-vivo measurements. When implants are integrated with bones after surgery, especially in aged individuals, their osseointegration can compromise the structural integrity of bones; for this reason, it is important to monitor the evolution of the mechanical properties of bones with some in-vivo diagnostic technique. In this study, we propose to integrate optical microsensing devices into bones. To simulate the working principle, a sensor is integrated with a 3-D printed bone. The sensing element is a dye-doped optical microlaser based on the morphology dependent resonance (MDR) shifts also called the whispering gallery mode phenomenon (WGM). When the microlaser is excited by a light source, the fluorescence from the dye couples with the optical resonances. These optical resonances are very sensitive to any perturbation of the microlasers’s morphology. Therefore, the local strain variation of the bone can be related to the shift of the optical resonances. This in-vivo technique monitors the biomechanical performance of bones with implants and prosthetics.

Solid State Optical Microlasers Fabrication via Microfluidic Channels

“…The average Q factor value was 2.9 × 10 4 and was comparable with the Q factor found in microlasers fabricated with other techniques. The quality factor Q is a measure of how resolute a sensor based on optical microlasers [1][2][3][4][5]9,10]. This means that the fabrication method did not affect the quality factor of the microlasers, or that the variation of the Q factor was below the instrument resolution.…”

“…Microscale circular structures that enable whispering gallery modes (WGMs) have been employed as passive and active elements for different applications such as non-linear optics, low threshold microlasers, filters, and sensors [1][2][3][4][5][6][7][8][9][10][11][12]. Different materials have been used for the fabrication of these organized microstructures such as polymers, crystals, and other exotic materials [13][14][15].…”