Gimbal-Less Two-Axis Electromagnetic Microscanner with Twist Mechanism.

Yangkyu Park,Sang-Jin Lee,Seunghwan Moon,Jong-Hyun Lee,Jaekwon Lee,Kwanghyun Kim

doi:10.3390/mi9050219

Abstract

We present an electromagnetically driven microscanner based on a gimbal-less twist mechanism. In contrast to conventional microscanners using a gimbal-less leverage mechanism, our device utilizes a gimbal-less twist mechanism to increase the scan angle in optical applications requiring a large scanning mirror. The proposed gimbal-less scanner with twist mechanism increases the scan angle by 1.55 and 1.97 times for the slow and fast axes, respectively, under the same force; 3.64 and 1.97 times for the slow and fast axes, respectively, under the same maximum stress, compared to the gimbal-less leverage mechanism. The scanner with a 3-mm-diameter mirror and a current path composed of a single-turn coil was fabricated, and it showed the maximum scan angle of 5° (quasi-static) and 22° (resonant) for the slow and fast axes, respectively. The experimentally estimated crosstalk was as small as 0.47% and 0.97% for the fast and slow axes affected by the other axes, respectively, which was determined using a newly employed methodology based on fast Fourier transform.

Highlights

Microelectromechanical systems (MEMS)-based optical microscanners have been widely developed in various optical applications owing to their advantages such as low power consumption, high speed, compact size, and low production cost [1]
Electromagnetic actuation can provide relatively large torque and fast response time. This causes electromagnetic scanners to be preferable in applications requiring large scan angles and high speeds such as light detection and ranging (LiDAR)
Our device utilizes gimbal-less twist mechanism instead of gimbal-less leverage mechanism to increase the scan angle for optical applications requiring a large size mirror

Summary

Introduction

Microelectromechanical systems (MEMS)-based optical microscanners have been widely developed in various optical applications owing to their advantages such as low power consumption, high speed, compact size, and low production cost [1]. Thermal actuation has a relatively slow response time, even though a large scan angle can be achieved at a low actuation voltage [1,13]. Electromagnetic actuation can provide relatively large torque and fast response time. This causes electromagnetic scanners to be preferable in applications requiring large scan angles and high speeds such as LiDAR. In optical applications requiring a large mirror, the expected scan angle would be small because a large distance between the hinge (called for rotation transformer) and mirror reduces the leverage amplification ratio. Huollwifeyvetrh, eintooprtqicualeaaptpltihcaetiopnasssive current requiring a large mirror, the expected scan angle would be small because a large distance between path. FigurFeig2u.reFi2n. itFeineilteemeleenmteannt aalnyasliyssi(sFE(FAE)Af)ofrorddrirviviningg cchhaarraacctteerriissttiiccss.. ((aa)) SSimimuulalatetdedmmodoedl;el(;b)(bs)tastitcatic displdaicsepmlaecenmt efnotrfosrloslwow-a-xaxisis ssccaann;;(c()cm) amgnaigfineidfiveidewvfioerwthefodrispthlaecedmisepntlaocfetmwoenhtinogefs.twThoe shiminugleasti.onThe simuwlaatsiocnonwdausctceodnudnudcetredanuanpdpelrieadnfoarpcpe loifed86f2o.4rcμeNofo8n6e2a.c4hμrNotaotnorefaocrhthreostalotworafxoirs.the slow axis

Device Configuration

Magnetic Field

Results and Discussion

Conclusions