A Composite Hysteresis Model in Self-Sensing Feedback Control of Fully Integrated <inline-formula> <tex-math notation="LaTeX">$\mathrm{VO_2}$</tex-math> </inline-formula> Microactuators

Abstract

In this paper a composite hysteresis model is proposed for self-sensing feedback control of vanadium dioxide (VO2)-integrated microactuators. The deflection of the microactuator is estimated with the resistance measurement through the proposed model. To capture the complicated hysteresis between the resistance and the deflection, we exploit the physical understanding that both the resistance and the deflection are determined by hysteretic relationships with the temperature. Since direct temperature measurement is not available, the concept of temperature surrogate, representing the constant current value in Joule heating that would result in a given temperature at the steady state, is explored in the modeling. In particular, the hysteresis between the deflection and the temperature surrogate and the hysteresis between the resistance and the temperature surrogate are captured with a generalized Prandtl-Ishlinskii (GPI) model and an extended generalized Prandtl-Ishlinskii (EGPI) model, respectively. The composite self-sensing model is obtained by cascading the EGPI model with the inverse GPI model. For comparison purposes, two algorithms, based on a Preisach model and an EGPI model, respectively, are also used to estimate the deflection based on the resistance measurement directly. The proposed self-sensing scheme is evaluated with proportional-integral (PI) control of the microactuator under step and sinusoidal references, and its superiority over the other schemes is demonstrated by experimental results.

Vanadium Dioxide: The Multistimuli Responsive Material and Its Applications

“…The MIT in VO 2 leads to the thermal expansion coefficient change between VO 2 and other materials, which make it can be used in some novel mechanical devices. Joule heating generated by current passing VO 2 can also cause a huge flexural and mechanical change of the VO 2 composite device …”

Modeling of MEMS Mirrors Actuated by Phase-Change Mechanism

“…This component was modeled as a linear term and a quadratic term in previous studies [26,27]. The following linear model is adopted in this work:${\mathrm{\Gamma }}_E\left(T^{\prime }\right)=-k_0{T}^{\prime },$ where $k_0$ is a constant term related to thickness, modulus of elasticity, and thermal expansion coefficients of VO 2 layer and SiO 2 layer, and the negative term is introduced due to the fact that the thermal expansion-induced force has an opposite direction as the phase transition-induced force.…”

“…The Preisach model is thus adopted in this work. In order to control the systems with hysteresis, feedforward control can be realized by inverting the hysteresis nonlinearity [26], and feedback control can also be implemented, where the feedback signal can be obtained based on external sensors or with self-sensing methods [27]. In self-sensing, the correlation between the electrical and mechanical properties across the transition is utilized [28].…”

Rolled-up single-layered vanadium oxide nanomembranes for microactuators with tunable active temperature

“…Recently, various microactuators have been investigated based on bilayer structures. These microactuators were generally constructed by depositing a structural layer on a VO 2 film, followed by an etching process to define the anchor and pattern [12]. The initial state of these microactuators was altered by the deposited materials with tunable properties and internal strain [13].…”

“…Unfortunately, the active layer in these microactuators can only be set as the bottom layer. Moreover, deposition of VO 2 requires a high temperature [7][8][9][10][11][12][13], which means few materials of underlayer materials with VO 2 can be chosen as strain layer for a VO 2 microactuator. So the shrinking of the VO 2 layer results in downward bending during actuation or unfolding behavior to a bended microactuator.…”