Design and Fabrication of a Kirigami-Inspired Electrothermal MEMS Scanner with Large Displacement

Abstract

Large-displacement microelectromechanical system (MEMS) scanners are in high demand for a wide variety of optical applications. Kirigami, a traditional Japanese art of paper cutting and folding, is a promising engineering method for creating out-of-plane structures. This paper explores the feasibility and potential of a kirigami-inspired electrothermal MEMS scanner, which achieves large vertical displacement by out-of-plane film actuation. The proposed scanner is composed of film materials suitable for electrothermal self-reconfigurable folding and unfolding, and microscale film cuttings are strategically placed to generate large displacement. The freestanding electrothermal kirigami film with a 2 mm diameter and high fill factor is completely fabricated by careful stress control in the MEMS process. A 200 μm vertical displacement with 131 mW and a 20 Hz responsive frequency is experimentally demonstrated as a unique function of electrothermal kirigami film. The proposed design, fabrication process, and experimental test validate the proposed scanner’s feasibility and potential for large-displacement scanning with a high fill factor.

Review of Electrothermal Micromirrors

“…In 2021, Masaaki et al reported an electrothermal scanner, inspired by traditional Japanese origami, consisting of eight curved NiCr/SiN-bimorph actuators and a mirror plate ( Φ = 2 mm) with a hole [ 85 ], as shown in Figure 27 a. The released scanner ( Figure 27 b) generated a piston motion of 200 μm at a voltage of 25 V dc or at a power of 131 mW, as shown in Figure 27 c. Note that this origami inspired micromirror can only move vertically.…”

“… ( a ) Backside view of the mirror inspired by Japanese origami; ( b ) SEM images of the scanner; ( c ) curve of vertical displacement versus total voltage [ 85 ]. …”

Current Development on Origami/Kirigami‐Inspired Structure of Creased Patterns toward Robotics

“…[7] Copyright 2017, The American Association for the Advancement of Science. flat, soft, and flexible sheet, [109] which is well-known for its applications in flexible and stretchable electronics, [110][111][112][113] tunable mechanical metamaterials, [114] shape morphing, [58,115,116] and biomimetic devices, [117][118][119][120] because of its good performance in film adhesion. [121] The net-like multistable kirigami structures will be stretched and twisted when tensile load is applied, [48] where predicts the ultimate stress or strain is known to be complex due to the nonlinear effects arising from the out-of-plane buckling.…”

Mechanically Stable Kirigami Deformable Resonant Circuits for Wireless Vibration and Pressure Sensor Applications

“…Over the past decade, kirigami, the art of “paper cutting,” has significantly transformed the procedure of manufacturing flexible/deformable electronic devices. − Kirigami structures with one-and/or two-dimensional stretchability, along with and within the cutting plane directions, have been widely applied to manufacture various flexible/stretchable electronic devices. , In contrast, 3D kirigami structures with large out-of-plane deformability, normal to the cutting plane direction, have been proposed to fabricate the position, acceleration, deformation, vibration, and pressure sensors applied in robotics, virtual reality, structural health monitoring, and motion tracking. Generally, these sensors consist of wired connections or connection points and bulk materials that are critical in closed environments for wireless sensing.…”