Identification of the periodontal ligament material parameters using response surface method.

The orthodontic treatment can be guided by the finite element (FE) simulation of periodontal ligament (PDL) mechanical properties, and the biomimetic degree of FE simulation can be primarily affected by the material properties of the PDL. According to the principle of parameter inverse, a method: response surface (RS) method and FE inverse method were proposed to identify the material parameters of PDL. The Prony series viscoelastic FE model was established based on the relaxation experiment.

High resolution quartz flexure accelerometer based on laser self-mixing interferometry.

As common high-precision inertial sensors, quartz flexure accelerometers have a wide application prospect in low-cost inertial navigation systems. To ameliorate their resolution performance restricted by differential capacitance detection, we proposed a modified type of quartz flexure accelerometer based on an emerging optical technique named laser self-mixing interferometry, which is utilized to sense the displacement of a quartz pendulous reed, and then an equal and opposite force is accordingly produced to maintain the reed motionless relative to the inertial frame. The configuration and working principle of the improved accelerometer have been introduced and analyzed.

Injected current reshaping in distance measurement by laser self-mixing interferometry.

Self-mixing interferometry (SMI), as an extremely simple and compact laser range finding technique, is especially appropriate to develop minitype sensors for narrow space and small precision parts. In order to enhance the distance resolution performance of this technique, we described the mechanism of nonlinearity in laser frequency under injected current tuning, and proposed a current reshaping method to linearize the laser frequency to attain higher resolution in the scheme of SMI. The proof of nonlinearity was obtained through numerical simulation by considering the change of temperature and carrier concentration and experiment by complex wavelet analysis.