Piezoelectric Microactuator S-Drive Large Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MEMS actuators have limited operating ranges, typically only capable of motion in the order of tens of microns, and often require external position feedback systems, which restricts their application in environments requiring larger displacements.
Innovation Solution
The development of a piezoelectric microactuator using a series-connected S-drive configuration with multiple piezoelectric elements and electrodes, allowing for large translational and rotational deflections by applying voltage across the electrodes to deform the piezoelectric elements, enabling deflections greater than 100 microns and rotations exceeding 10 degrees.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional MEMS actuator schemes are used, then the device can be fabricated on silicon wafers, but the operating range is limited to tens of microns
Solution Approach 1:
The actuator divides the piezoelectric elements into multiple segments arranged in an S-shaped configuration. Each segment contributes to the overall deflection, allowing the total operating range to exceed what a single continuous element could achieve while maintaining compatibility with standard silicon wafer fabrication processes.
Solution Approach 2:
The invention transitions from linear actuation to a two-dimensional S-shaped deflection pattern. By arranging piezoelectric elements in alternating pairs that deflect in opposite directions, the actuator achieves lateral displacement in addition to vertical motion, effectively increasing the operating range without requiring longer elements.
2Device complexity
If existing MEMS actuators are used, then the structure can be simple, but position feedback external to the MEMS is required
Solution Approach 1:
The piezoelectric elements serve dual functions: actuation and sensing. The same elements that generate mechanical displacement through voltage application also generate electrical charge when subjected to mechanical stress, enabling built-in position feedback without adding separate sensing components.
Solution Approach 2:
The actuator incorporates inherent feedback capability through the piezoelectric effect. By monitoring the electrical charge generated by the piezoelectric elements in response to applied stress, the system can determine its own position without requiring external sensors, creating a self-contained actuation and sensing system.
3Device complexity
If single-layer piezoelectric motors are used, then the design is simple, but the deflection magnitude is limited
Solution Approach 1:
The actuator divides the piezoelectric elements into multiple segments arranged in an S-shaped configuration. Each segment contributes to the overall deflection, allowing the total operating range to exceed what a single continuous element could achieve while maintaining compatibility with standard silicon wafer fabrication processes.
Solution Approach 2:
The invention transitions from linear actuation to a two-dimensional S-shaped deflection pattern. By arranging piezoelectric elements in alternating pairs that deflect in opposite directions, the actuator achieves lateral displacement in addition to vertical motion, effectively increasing the operating range without requiring longer elements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution provides a wide operating range and built-in position sensing, enabling applications in biomedical engineering, optics, and micro/nano-assembly without the constraints of clean environments or high power consumption, with simulated performance showing capabilities beyond existing piezoelectric actuators.
Implementation Method 1
voltage applied to the first electrode causes deformation of a first piezoelectric element of the first pair and a second piezoelectric element of the second pair
Data Source
AI summary
Actuators using piezoelectric drives, S-drives, or S-flexures are disclosed. The actuators can include S-drives connected in series to deflect substantially in a common deflection direction. The actuators can also include pairs of piezoelectric elements connected together for rotation in the plane of the pairs. An arm assembly and a forearm assembly can each have a plurality of S-flexures for deflection along substantially orthogonal axes.