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This paper reports on a novel CMOS-based silicon microprobe for high-density intracortical stress mapping. In contrast to existing systems, square p-type field effect transistors (FET) with four source/drain contacts (piezo-FETs) are integrated on the slender, needle-like probe shaft. In total, 345 stress sensors are arranged in five columns (x/y-pitch of 51.4/26.6 ??m) along the 180-??m-wide shaft...
Two novel, wireless, batteryless, less-invasive blood pressure sensing microsystems based on circular cuff and flat cuff configurations are developed for advanced biomedical application. Both systems employ an instrumented silicone cuff, wrapped around a blood vessel, for real-time blood pressure monitoring. The cuff is filled by silicone gel with an immersed MEMS pressure sensor and integrated electronic...
We report the first remote flight control of an insect using microfabricated flexible neuroprosthetic probes (FNPs) that directly interface with the animal's central nervous system. The FNPs have a novel split-ring design that incorporates the anatomical bi-cylinder structure of the nerve cord and allows for an efficient surgical process for implantation (Figure 1a). Additionally, we have integrated...
This paper presents a low temperature (200??C) CMOS-compatible fabrication process for integrating high-temperature deposited lead zirconate titanate (PZT) on thin film monocrystalline-silicon piezoelectric actuators, onto an RF substrate, and successful demonstration of this process for fabrication of metal-contact RF-MEMS switches. The patterned PZT/silicon multi-layer stack is transfer-bonded from...
This paper describes the design, and implementation of novel dual-axes confocal microscopes that use separate optical axes for illumination and collection of light. This configuration can achieve subcellular resolution (< 5 ??m) with deep tissue penetration (> 300 ??m), high dynamic range, and large field of view. Moreover, scalability down to millimeter dimensions with a diffraction limited...
We present the first implantable MEMS drug delivery device that includes an electrochemical bellows pump, refillable drug reservoir, and dual regulation valve. Multiple drug pump configurations were fabricated, assembled, and tested. Delivery of agents for cancer radiation reduction was demonstrated. In vivo chronic delivery of radiation sensitizing agents in the form of small interfering (siRNA)-gold...
This paper presents a novel multi-step three dimensional microassembly of passive-circuit-mesh, conductive beads, and LED chips to fabricate a flexible, bright, and wide viewing angle display. A novel flexible display architecture is proposed. To deliver this design, we focus our efforts on the multi-batch assembly integration. A 3-by-3 light-emitting diode array with a chip size of 610 ??m by 610...
We present a biasing technique and a novel oscillator architecture for the elimination of frequency drifts in resonant electrostatic MEMS that are caused by the motion of charge present within dielectrics. We demonstrate more than two orders of magnitude improvement in stability for a test device operating as a frequency reference at 1.077 MHz, reducing frequency drift from more than 100 Hz over 3...
This paper reports on the design and experimental verification of a new class of nanoscale gravimetric sensors based on ultra-thin-film AlN contour-mode resonant sensor (CMR-S) functionalized with ss-DNA and connected to a chip-based self-sustaining oscillator loop (fabricated in the ON semiconductor 0.5 ??m CMOS process) for direct frequency read-out. The 220 MHz oscillator based on the ultra-thin...
We present a novel hydrogen sensor that is based on large arrays of chemically actuated electromechanical nanoswitches, realized by nanogaps in palladium (Pd). An individual switch consists of a trimorph poly-Si/Ti/Pd structure and a fixed Ti/Pd electrode, separated by an approximately 10-15 nm wide nanogap. The volume expansion of Pd at hydrogenation bends the trimorph vertically and creates an electric...
In this research, we present a chip based capillary electrochromatography (CEC) carrying out a highly efficient separation of biomolecules through gradient hydrophobic stationary phase (GHSP) provided by multiwalled carbon nanotubes (MWCNTs) nanocolumns. 4-azidoaniline was employed for the surface modification of the MWCNTs to form a gradient stationary phase by a photochemical reaction through a...
We have developed an all-in-one microfluidic platform that integrates sample preparation and gene analysis on one single device. Our platform takes the advantage of the silica superparamagnetic particle (SSP) based solid phase extraction (SPE) and an all-in-one scheme that performs cell lysis, DNA binding, washing, elution and polymerase chain reaction (PCR) in the same reaction chamber, which greatly...
In this work, we develop a miniaturized system for DNA extraction and polymerase chain reaction (PCR). DNA is extracted from whole blood sample by using silica coated magnetic beads. Electromagnetic actuation is employed to manipulate the magnetic beads for transporting DNA molecules in fluidic channels. Thermo-pneumatic valves with low temperature elevation are integrated into the microfluidic chip...
We present a cell handling method using magnetically functionalized microplates. Rectangular-shaped permalloy inside the microplates enables the plates to rotate or flip upside down by magnetic field. We conduct two kinds of cell handling experiments: (1) rotating cells for the precise positioning of cell nucleus and (2) flipping over the microplate for culturing different types of cells on both sides...
We report on a new light-actuated digital microfluidics device which is capable of using on demand, `virtual' electrodes formed by a data projector to enable large-scale, parallel manipulation of arbitrarily sized droplets. The device features a thin, high-quality Al2O3 film deposited via atomic layer deposition (ALD) which allows aggressive scaling of the dielectric thickness, while maintaining high...
This work presents the development of a capacitive tactile and shear-stress sensing array which can be easily and reliably fabricated by using MEMS techniques and flexible printed circuit board (FPCB) technologies. The sensing array consists of two micromachined PDMS structures and an FPCB with sensing electrodes. Each shear sensing element comprises four capacitive sensing element arranged in 2??2...
This paper demonstrates the real-time sensing of enzymatic reactions on a DNA bundle trapped by silicon nanotweezers. The digestion of DNA in protein solution (Hind III) is monitored by tracking the change in frequency response of the immersed tweezers. This new direct biomechanical detection clears the way for systematic bio tests at the molecular level by an integrated MEMS device.
This paper describes the formation of a micro-scale gel strand constructed with self-assembled supramolecular nanofibers fabricated in a microfluidic channel. The supramolecular nanofibers are highly aligned along the axis of the gel strand; this morphology is very different from the bulk gel. Moreover, we found that small molecules are able to diffuse along the supramolecular-nanofiber's axis. We...
Electroporation, in which electric pulses are applied to create transient pores in the cell membrane, is widely used to introduce biologically active molecules into cells. Here we report a novel electroporation chip with great performance and good compatibility with the standard multi-well plate used in biological research. We demonstrated a prototype chip integrating with a 12-well plate and successfully...
The system performance of an antibody-functionalized microchamber array, developed for selectively binding target cancer cells, is quantitatively characterized. The devices are designed to allow accurate counting of loaded and captured cells from heterogeneous suspensions. Specific interaction between cancer cell receptors and immobilized surface ligands has been demonstrated under static conditions...
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