In this paper, we discuss a novel, mixed mode 3D XYZ scanner built within a single foundry process. The device has a large range of motion in X, Y and Z (14.0 μm in X,Y and 97.9 μm in Z) and can also rotate about two axes (7.4°), making it a 5 degree of freedom scanner. Vertical actuation can be accomplished with both thermal actuators, which have a larger range of motion, and capacitive actuators, which are faster, responding fully up to 3.2 kHz. Although it is useful for many applications, including scanning probe microscopy, micrometer scale optical microscopy, and manipulation of biological objects, the device was designed to be a 3D scanner for spray-painting atoms upon a surface with nanoscale precision and resolution for nanofabrication. Demonstrating the ability to combine the device with other complicated MEMS systems, it is integrated with an XY scanner designed to serve as a shutter to control the flow of atoms. The full system has 7 degrees of freedom and 12 actuation motors, and because it is built in a low cost commercial foundry with a robust, stable process, it is easy and inexpensive to fabricate multiple copies or integrate into other complicated systems, making a system of systems.
This work was funded by DARPA Atoms to Product (A2P) Program/Air Force Research Laboratory (AFRL) contract no. FA8650-15-C-7545
Direct laser writing (DLW) is an advanced fabrication technique that allows users to create complex 3D microstructures from polymer precursors. These microstructures can be integrated with micro-electromechanical systems (MEMS) actuators. MEMS actuators provide a convenient platform for interacting with the intricate microstructures, either to characterize their mechanical properties or cause them to deform. Structures are fabricated directly onto electrostatic comb drives and chevron thermal actuators that are produced using a commercial foundry process. By applying a voltage to the MEMS actuators, highly controlled deformation of these microstructures is observed. Mechanical behaviors of microstructures produced with different materials and fabrication conditions are compared. MEMS-DLW integration is a convenient approach to characterizing the mechanics of DLW microstructures and may well lead to a new class of dynamic 3D devices for applications ranging from tissue engineering to imaging.
The fabrication of metallic electromagnetic meta-atoms on a soft microstructured polymer scaffold using a MEMS-based stencil lithography technique is demonstrated. Using this technique, complex metasurfaces that are generally impossible to fabricate with traditional photolithographic techniques are created. By engineering the mechanical deformation of the polymer scaffold, the metasurface reflectivity in the mid-infrared can be tuned by the application of moderate strains.
Using a microelectromechanical systems (MEMS)-based Fab-on-a-Chip, we quench-condense lead thin-films. Suppressing the formation of lead islands makes it possible to grow a homogeneous and continuous film as thin as 2 nm, without the use of an adhesion layer. Thermal cycling from 3 K to as low as 10 K reveals irreversible annealing of the thin-film characteristic of a metastable state. The transition to the stable state is smooth and is completed by cycling the temperature above ∼42 K, where a distinctive resistance minimum is observed. This resistive minimum is accompanied by an unexpected peak in the superconducting transition temperature. After further thermal cycling, the standard metallic/superconductive behavior is established. The MEMS-based approach yields a platform for systematic studies of quench-condensed thin-film materials, making an intriguing parameter space of mesoscopic physics experimentally accessible.
Micro/nanoelectromechanical systems (MEMS/NEMS) provide the engineer with a powerful set of solutions to a wide variety of technical challenges. However, because they are mechanical systems, response times can be a limitation. In some situations, advanced engineered drive techniques can improve response times by as much as a thousand fold, significantly opening up the application space for MEMS/NEMS solutions.
We present a microelectromechanical systems (MEMS) tunable metamaterial, Fabry-Perot interferometer with a widely tunable mid-infrared response. An array of subwavelength holes in a gold film is suspended above a gold reflector, forming an interferometer cavity whose length can be modulated over a range of 1.7 to 21.67 mu m using MEMS electrostatic actuation. Reflectance spectra exhibit the convolution of extraordinary optical transmission through the holes and Fabry-Perot resonances with free spectral ranges from 2900 to 230.7 cm(-1). Measuring the free spectral range enables us to perform in situ interferometric calibration of the cavity length. We present a simple analytical model that describes the experimental and simulated results. This device shows promise as a surface-enhanced sensing substrate with a tunable spectral response.
In this paper we discuss the development of a MEMS-based solid state atom source that can provide controllable atom deposition ranging over eight orders of magnitude, from ten atoms per square micron up to hundreds of atomic layers, on a target ∼1 mm away. Using a micron-scale silicon plate as a thermal evaporation source we demonstrate the deposition of indium, silver, gold, copper, iron, aluminum, lead and tin. Because of their small sizes and rapid thermal response times, pulse width modulation techniques are a powerful way to control the atomic flux. Pulsing the source with precise voltages and timing provides control in terms of when and how many atoms get deposited. By arranging many of these devices into an array, one has a multi-material, programmable solid state evaporation source. These micro atom sources are a complementary technology that can enhance the capability of a variety of nano-fabrication techniques.
Semiconductor fabs are large, complex industrial sites with costs for a single facility approaching $10B. In this paper we discuss the possibility of putting the entire functionality of such a fab onto a single silicon chip. We demonstrate a path forward where, for certain applications, especially at the nanometer scale, one can consider using a single chip approach for building devices with significant potential cost savings. In our approach, we build micro versions of the macro machines one typically finds in a fab, and integrating all the components together. We argue that the technology now exists to allow one to build a Fab on a Chip.