University of Michigan

The Board of Regents Acting for and on Behalf of the University of

Enertia Microsystems Inc.

Other

Epack, Inc.

Khalil Najafi

Jae Yoong Cho

Kensall D Wise

Navid Yazdi

Rebecca L Peterson

Sang Woo Lee

Ethem Aktakka

Tal Nagourney

Sang-Hyun Lee

Hanseup S Kim

Guohong He

Ali Darvishian

Luis P Bernal

Peter D Washabaugh

Behrouz Shiari

Yemin Tang

Yi Yuan

Mahdi Sadeghi

Daniel Egert

Liwei Lin

Iman Shahosseini

Seyed Amin Sandoughsaz Zardini

Yu-Ting Cheng

Joseph M Giachino

Junseok Chae

Haluk Kulah

Jay Mitchell

Onnop Srivannavit

Aaron A Astle

Chunbo Zhang

Asli B Ucok

Tsung-Kuan A Chou

Timothy J Harpster

Chou Tsung-Kuan

Arvind Salian

James John McCullagh

Zongliang Cao

Sajal Singh

Jeffrey Gregory

Tzeno Galchev

Maysam Ghovanloo

Ali Besharatian

Brian H Stark

Disclosed herein are vibratory gyroscopes comprising hollow shell resonators and methods of fabricating thereof. Specifically, a vibratory gyroscope comprises a support substrate comprising a substrate primary surface and a resonator support surface, substantially perpendicular to the substrate primary surface. The gyroscope also comprises a hollow shell resonator comprising a resonator inner surface and a resonator outer surface such that the resonator inner surface defines a recessed region with a recessed region opening facing the substrate primary surface. At least one of the inner or outer resonator surfaces is attached to the resonator support surface of the support substrate adjacent to the inner edge surface of the resonator. The inner edge surface can be formed by a hollow stem with or without opening through this surface. Furthermore, the resonator support surface can be a continuous cylindrical surface or a segmented surface.

Vibratory gyroscopes with resonator attachments

Various methods of manufacture can produce three-dimensional, high density, high-electrode probe arrays that can advantageously be used in neural-based applications. In one example, deep reactive ion etched (DRIE) ultra-high aspect ratio holes are etched in silicon and refilled with multiple films to a high density array of individual probes, each probe having individual recording and/or stimulation sites or tips. Using a DRIE lag effect technique can help control tip sharpness and electrode length, allowing for narrow, long, and dense needles to be formed side-by-side in a single array. In some examples, multimodal probe arrays are manufactured, with some probes having a recording/stimulating site, other probes having a waveguide, and yet other probes having a microfluidic channel.

Method of manufacturing a probe array

Three-dimensional (3D) micro-scale shells are presented with openings of various sizes and geometries on the surface. The shell consist of a suspended ring-shaped resonator, multiple support beams, a support post, and a cap region that connects the support beams to the support post. Shells with openings of various sizes and geometries allow the creation of micro electromechanical systems (MEMS) sensors and actuators with a wide range of engineered mechanical and electrical properties. The openings on the shell surface can, for example, control the mechanical quality factor (Q) and resonance frequencies of the shell when the shell is used as a suspended proof mass of a mechanical resonator of a vibratory gyroscope. The shells can also serve as mechanical supporting layers and/or an electrode connection layer for MEMS actuators and sensors that use 3D shells as proof masses.

Three dimensional microstructures with selectively removed regions for use in gyroscopes and other devices

Micro-scale thermoelectric devices having high thermal resistance and efficiency for use in cooling and energy harvesting applications and relating fabricating methods are disclosed. The thermoelectric devices include first substrates substantially parallel with second substrates. Scaffold members are deposited between the first and second substrate. The scaffold members include a plurality of cavities having sidewalls. The scaffold members may be formed from the second substrate. The sidewalls are substantially vertical with respect to the second substrate. The sidewalls may be substantially parallel. Thermoelectric materials are deposited on the sidewalls.

Thermoelectric micro-module with high leg density for energy harvesting and cooling applications

Gyroscopes are sensors that measure angular rate and angular orientation. A three-dimensional fused silica micro shell rate-integrating gyroscope is presented. One aspect of the gyroscope includes the use of optical sensors to detect motion of the resonator. The proposed gyroscope is attractive because it achieves several magnitudes higher accuracy as well as high vibration and shock insensitivity from a novel resonator design as well as other unique manufacturing processes.

Gyroscope and fabrication process

Methods for fabricating three-dimensional microstructures are provided. The method includes disposing a reflow material on a mold, heating the reflow material, and creating a pressure gradient across the reflow material to reflow the material towards a bottom surface of the mold. The mold includes a molding region, a boundary region, and a thermal-isolating region disposed therebetween. The molding region includes a cavity and a projection projecting upwards from a bottom surface of the cavity. The thermal-isolating region includes at least one pocket formed adjacent to and along a perimeter of the cavity of the molding region. During heating, the temperature of the molding region is higher than that of the boundary region and the thermal-isolating region controls the thermal conductivity and mass therebetween. The material reflows towards the bottom surface of the cavity and the protrusion helps shapes the reflow material to form a substantially symmetrical three-dimensional microstructure.

Thermal control mold for making three-dimensional microstructures

An energy harvester coupled to a vibration source includes a housing, a transducer, and an amplifier. The transducer may have a first part and a second part. The first part and the second part may move relative to each other along a central axis in response to a motion from the vibration source. The amplifier is coupled to the housing and operable to amplify an amplitude of the motion received from the vibration source. The amplifier has an input member coupled to the vibration source and an output member coupled to the first part of the transducer. The input member moves at a distance Din response to the motion from the vibration source. The output member moves the first part of the transducer in response to the input member moving. The first part of the transducer moves along the central axis by a distance D, where D&#x3e;D

Vibrational energy harvester with amplifier having gear assembly

An electromagnetic transducer includes a magnetic assembly and a coil assembly. The magnetic assembly may include an inner magnet subassembly and an outer magnet subassembly. The inner magnet subassembly and the outer magnet subassembly each have a plurality of axial magnets arranged in a stacked configuration with a spacer disposed between vertically adjacent axial magnets. The coil assembly includes an inner coil subassembly and an outer coil subassembly. The inner coil subassembly is disposed between the inner magnet subassembly and the outer magnet subassembly, and the outer coil subassembly is disposed around the outer magnet subassembly. The coil assembly and the magnetic assembly are configured to move relative to each other.

Electromagnetic energy transducer

A method for fabricating three-dimensional microstructures is presented. The method includes: disposing a substantially planar reflow material between two molds; heating the reflow material while the reflow material is disposed between the two molds; and reflowing the reflow material towards the bottom surface of one of the molds by creating a pressure gradient across the reflow material. At least one of molds includes geometrics features that help to shape the reflow material and thereby form a complex three-dimensional microstructure.

Three dimensional microstructures and fabrication process

Three-dimensional microstructure devices having substantially perfect alignment and leveling of a three-dimensional microstructure with respect to a substrate having a plurality of discrete electrodes and relating fabricating methods are disclosed. Seed layers are deposited onto the discrete electrodes of the substrate, and the three-dimensional microstructure is bonded adjacent to the seed layers. A substantially uniform sacrificial layer is deposited onto exposed surfaces of the three-dimensional microstructure. A plurality of first gaps exists between the seed layers and corresponding regions of the sacrificial layer. Conductive layers are deposited to fill the first gaps. The sacrificial layer is dissolved to create a second plurality of gaps between the conductive layers and the corresponding regions of the three-dimensional microstructure. The second gaps are substantially uniform.

Assembly processes for three-dimensional microstructures

A resonator array comprises substantially paralleled first and second resonant layers having resonating masses. A first set of lateral drive electrodes cause the first resonating mass to vibrate along an axis in a first geometric plane. A second set of lateral drive electrodes cause the second resonating mass to vibrate along an axis in a second geometric plane in an opposite direction of the first resonating mass by about 180 degrees. Rotation in the system causes the masses to vibrate out-of-plane in opposite directions. The opposite vibrational directions of the first and second resonating masses produces a balanced system with small motion in a bonding area between the stacked resonators. As a result, there is minimal propagation of mechanical waves from the balanced system to a substrate resulting in lower anchor loss and a high Q-factor.

Stacked balanced resonators

A micropump assembly is comprised of modular stacked pump stages. The modular pump stages are preferably stacked vertically on top of each other. The stacked design allows each pumping chamber to be compressed by two pumping membranes and thereby provide twice the compression as compared to conventional planar pump designs. The stacked design also eliminates the need for bidirectional movement of the pumping membrane. Lastly, the number of stacked pumping stages can be changed post-fabrication to achieve the required pressure for a given application.

Modular stacked variable-compression micropump and method of making same

Techniques are presented for fabricating transducers and other types of microstructures having high aspect ratios. To achieve high aspect ratios, wafers are etched from both sides for example using deep reactive ion etching. The three-dimensional structure is designed to have an overall footprint less than four hundred micrometers with a thickness on the order of 0.5-2 millimeters as compared to conventional planar devices.

Capacitive-based transducer with high aspect ratio

Growing community of inventors

Ann Arbor, MI, United States of America

Khalil Najafi