University of Michigan

Wisconsin Alumni Research Foundation

Kenichi Takahata

Yogesh B Gianchandani

Kensall D Wise

Juda L Shohet

Ponnambalam Selvaganapathy

Andrew D DeHennis

Larry L Chu

An assembly and planar structure for use therein which is expandable into a 3-D structure such as a stent and device for making the planar structure are provided. The planar structure permits the use of planar batch manufacturing technologies to fabricate coronary artery stents. Stents with different wall patterns are fabricated from 50 &#x3bc;m thick stainless steel foil using micro-electro-discharge machining, and expanded to tubular shapes by using angioplasty balloons. The stents are free-standing. The free-standing stents exhibit diameter variations of &#x3c;&#xb1;4%, almost zero radial recoil after deflation of the balloon, and longitudinal shrinkage of &#x3c;3% upon expansion. A variation of the stents uses breakable links to provide additional customization of electrical and mechanical properties. Loading tests reveal that the radial strengths match commercially available stents, while longitudinal compliance, at 0.02 m/N for a 4 mm long section of the stent, is substantially higher.

Assembly and planar structure for use therein which is expandable into a 3-D structure such as a stent and device for making the planar structure

Disclosed herein is an electromagnetic flow sensor device for monitoring flow of fluid in a channel. The sensor device includes a first electrode to be disposed along the channel and in communication with the fluid, a second electrode to be disposed along the channel and in communication with the fluid, and a radially expandable frame to structurally support the first electrode and the second electrode while conforming to the channel to position the first electrode and the second electrode along the channel. The device may also include an antenna coupled to the first and second electrodes to wirelessly provide an indication of a voltage induced between the first and second electrodes. In some embodiments, the radially expandable frame includes an insulating link such that the first and second electrodes are not electrically connected via the radially expandable frame. The sensor device may also include a structure having an inductance coupled to the first and second electrodes to wirelessly provide an indication of the induced voltage.

Electromagnetic flow sensor device

Disclosed herein is a stent device useful for maintaining the patency of a lumen while monitoring an intraluminal characteristic. The device includes a structure having a set of extendible bands that are capable of plastic deformation to form a scaffolding having an inductance, and further includes a capacitance coupled to the set of extendible bands and responsive to the intraluminal characteristic. The capacitance and the inductance form a tank circuit after the plastic deformation of the set of extendible bands to enable wireless transmission of an indication of the intraluminal characteristic.

Antenna stent device for wireless, intraluminal monitoring

A micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate are provided. The probe apparatus includes an integrated scanning tip and a dither actuation mechanism. The actuation is achieved using a bent-beam electrothermal actuator, and the probe tip is insulated from the actuator with a wide isolation gap. The device is fabricated by a modified micro electro-discharge machining process which allows electrical isolation within the micromachined structure using an epoxy plug. The apparatus may be used to measure changes in the external surface potential of a microfluidic channel as a function of varying pH of liquid inside the channel. The apparatus also may be used to map embedded charge in a thin layer on a substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.

Micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate

A micro-electro-discharge machining apparatus includes a substrate, a plurality of electrically conductive electrodes on the substrate arranged in an array, and a plurality of electrical interconnect lines formed on the substrate extending to one or more of the electrodes. An electrical power source is connected from one of its terminals through a resistor to each of the interconnect lines and from its other terminal to a workpiece to be machined. The electrodes connected to different interconnect lines may charge and discharge independently of each other, speeding up the machining process. An interconnect line may extend individually to each electrode so that all of the electrodes can charge and discharge independently of the others. The capacitor that is charged to produce the discharge voltage may be a separate discrete capacitor or a conductive substrate.

Micro-electro-discharge machining method and apparatus

Micro-electro-discharge machining is carried out utilizing a semiconductor array electrode having a substrate with a face surface and electrode protrusions extending from the face surface. The array electrode may be formed by lithographically patterning a semiconductor wafer such as a silicon wafer utilizing lithographic techniques of the type used in semiconductor device processing. The electrode protrusions in the surface of the substrate may be coated with a conducting metal. The electrode is positioned adjacent to a workpiece and a power supply is connected to the electrode and the workpiece to charge a capacitor until discharge takes place between the electrode protrusions and the surface of the workpiece, to electro-discharge-machine the workpiece to replicate the pattern of electrode protrusions into the workpiece. The semiconductor electrode is formed to be consumed during the machining process, during which many individual workpiece elements can be micromachined in parallel to provide rapid and economical production of micromachined parts.

Growing community of inventors

Ann Arbor, MI, United States of America

Kenichi Takahata