Related Experiment Video
Updated: May 18, 2026
A Polymer-based Piezoelectric Vibration Energy Harvester with a 3D Meshed-Core Structure
Published on: February 20, 2019
A piezoelectric active mirror suspension system embedded into low-temperature cofired ceramic
Maciej Sobocinski1, Mikko Leinonen, Jari Juuti
1Microelectronics and Materials Physics Laboratories, Electronics Materials, Packaging, and Reliability Techniques Research Group of Infotech Oulu, University of Oulu, Oulu, Finland. maciej@ee.oulu.fi
This study introduces a new way to create an active mirror system using a material called low-temperature cofired ceramic (LTCC). The mirror is embedded into the LTCC structure, which acts as both a support and a conductor. The system uses piezoelectric materials to control mirror movement and angle. The researchers tested the system's performance and found it could move the mirror by up to 1 micrometer and adjust the angle by 0.06 degrees. The structure also showed stable resonance frequencies, suggesting it could be used in optical devices like tunable filters. The study demonstrates that LTCC can be a useful platform for integrating piezoelectric components into compact mirror systems.
Area of Science:
- Microsystem engineering within embedded electronics
- Piezoelectric materials in optical systems
- LTCC-based sensor fabrication
Background:
Low-temperature cofired ceramic (LTCC) is widely recognized for its adaptability in creating complex electronic systems. Prior research has shown that LTCC can be used to fabricate sensors and microsystems efficiently. However, the integration of piezoelectric components into LTCC structures remains underexplored. Established methods focus on passive LTCC applications, but the dynamic behavior of embedded piezoelectric elements is less understood. This gap motivated the exploration of active mirror systems using LTCC. No prior work had resolved how to embed piezoelectric monomorphs into LTCC while maintaining structural integrity. The challenge lies in combining LTCC's mechanical properties with piezoelectric functionality. This paper's contribution is to demonstrate a novel approach to embedding piezoelectric structures into LTCC for active mirror applications.
Purpose Of The Study:
The aim of this study was to develop a piezoelectric active mirror suspension system integrated into LTCC. The specific problem addressed is the need for compact, high-performance mirror systems in optical applications. The motivation stems from the limitations of traditional mirror systems, which often require separate housing and control mechanisms. By embedding the mirror suspension into LTCC, the researchers sought to simplify the overall system design. The goal was to evaluate the feasibility of using LTCC as both a structural and functional component. This approach could reduce manufacturing complexity and improve system performance. The study focused on assessing the electrical and mechanical behavior of the embedded structure. The researchers aimed to determine whether the system could achieve precise mirror positioning and angular control.
Main Methods:
The researchers constructed an active mirror structure by stacking 20 LTCC layers using standard LTCC processing techniques. Each sample included a laser-micromachined lead zirconate titanate (PZT) structure that formed a monomorph during the firing process. The LTCC layers served as a package, passive support, and conductor substrate. A 4 mm diameter mirror substrate was mounted in the center of the monomorph arms. Each arm had independent signal electrodes and a shared ground electrode. The structure was tested using an LCR meter, network analyzer, and laser vibrometer. These tools measured electrical and electromechanical properties across different arms and the mirror. The researchers evaluated displacement and resonance frequencies to assess performance. The study focused on how the embedded structure responded to applied voltages.
Main Results:
The active mirror structure achieved more than 1 μm of DC displacement for mirror leveling. The system allowed small angular adjustments up to 0.06°. The first bending resonance frequency was detected at 11.31 kHz with a 4.0 μm displacement when the mirror was mounted. Without the mirror, the resonance frequency increased to 13.02 kHz with a 2.7 μm displacement. The structure demonstrated stable electrical and mechanical behavior under test conditions. The PZT monomorphs functioned effectively as actuators within the LTCC layers. The mirror positioning was consistent across multiple arms and electrodes. The system's performance met the requirements for tunable optical applications.
Conclusions:
The embedded piezoelectric mirror system in LTCC showed promising performance for optical applications. The structure achieved measurable displacement and angular control with minimal input. The researchers propose that the system could be used in tunable Fabry-Perot filters. The mirror structure allowed for precise positioning and angle adjustments. The LTCC layers provided structural and electrical support without compromising performance. The system's resonance frequencies suggest suitability for high-speed applications. The authors suggest that the design could be expanded to include multiple mirrors on both sides. The findings indicate that LTCC can serve as a versatile platform for integrating piezoelectric components.
Frequently Asked Questions
The system allowed angular adjustments up to 0.06°, according to the authors' measurements.
The PZT monomorph acts as an actuator, enabling displacement and angular control of the mirror.
The 4 mm diameter substrate was chosen to evaluate positioning performance in the center of the monomorph arms.
The researchers used an LCR meter, network analyzer, and laser vibrometer to assess electrical and mechanical behavior.
The first bending resonance frequency was detected at 11.31 kHz with a 4.0 μm displacement.
The authors propose the structure is feasible for tunable Fabry-Perot filter applications.
