Fabrication and in vivo testing of a sub-mm duckbill valve for hydrocephalus treatment.

Hydrocephalus is characterized by the accumulation of excess cerebrospinal fluid (CSF) in the cranium due to an imbalance between production and absorption of CSF. The standard treatment involves the implantation of a shunt to divert excess CSF into the peritoneal cavity, but these shunts exhibit high failure rates over time. In pursuit of improved reliability and performance, this study proposes a miniaturized valve designed to mimic the natural one-way valve function of the arachnoid granulations and thereby replace the shunts.

A Wireless Battery-Free Implant With Optical Telemetry for In Vivo Cortical Stimulation.

We present a 100 m-thick, wireless, and battery-free implant for brain stimulation through a U.S. Food and Drug Administration-approved collagen dura substitute without contact with the brain's surface, while providing visible-light spectrum telemetry to track the onset of stimulation.

Development of a novel, concentric micro-ECoG array enabling simultaneous detection of a single location by multiple electrode sizes.

Detection of the epileptogenic zone is critical, especially for patients with drug-resistant epilepsy. Accurately mapping cortical regions exhibiting high activity during spontaneous seizure events while detecting neural activity up to 500 Hz can assist clinicians' surgical decisions and improve patient outcomes.We designed, fabricated, and tested a novel hybrid, multi-scale micro-electrocorticography (micro-ECoG) array with a unique embedded configuration.

Wireless Stimulation of Motor Cortex Through a Collagen Dura Substitute Using an Ultra-Thin Implant Fabricated on Parylene/PDMS.

We present the design, fabrication, and in vivo testing of an ultra-thin (100 μm) wireless and battery-free implant for stimulation of the brain's cortex. The implant is fabricated on a flexible and transparent parylene/PDMS substrate, and it is miniaturized to dimensions of 15.6 × 6.

Passive and Flexible Wireless Electronics Fabricated on Parylene/PDMS Substrate for Stimulation of Human Stem Cell-Derived Cardiomyocytes.

In this paper, we report the development of a wireless, passive, biocompatible, and flexible system for stimulation of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMS). Fabricated on a transparent parylene/PDMS substrate, the proposed stimulator enables real-time excitation and characterization of hiPSC-CMs cultured on-board. The device comprises a rectenna operating at 2.

Hydrogel Check-Valves for the Treatment of Hydrocephalic Fluid Retention with Wireless Fully-Passive Sensor for the Intracranial Pressure Measurement.

Hydrocephalus (HCP) is a neurological disease resulting from the disruption of the cerebrospinal fluid (CSF) drainage mechanism in the brain. Reliable draining of CSF is necessary to treat hydrocephalus. The current standard of care is an implantable shunt system.

Modeling optical design parameters for fine stimulation in sciatic nerve of optogenetic mice.

Optogenetics presents an alternative method for interfacing with the nervous system over the gold-standard of electrical stimulation. While electrical stimulation requires electrodes to be surgically embedded in tissue for in vivo studies, optical stimulation offers a less-invasive approach that may yield more specific, localized stimulation. The advent of optogenetic laboratory animals-whose motor neurons can be activated when illuminated with blue light-enables research into refining optical stimulation of the mammalian nervous system where subsets of nerve fibers within a nerve may be stimulated without embedding any device directly into the nerve itself.

Optogenetic modulation of cortical neurons using organic light emitting diodes (OLEDs).

Objective: There is a need for low power, scalable photoelectronic devices and systems for emerging optogenetic needs in neuromodulation. Conventional light emitting diodes (LEDs) are constrained by power and lead-counts necessary for scalability. Organic LEDs (OLEDs) offer an exciting approach to decrease power and lead-counts while achieving high channel counts on thin, flexible substrates that conform to brain surfaces or peripheral neuronal fibers.

A compact, low-cost, quantitative and multiplexed fluorescence detection platform for point-of-care applications.

An effective method of combating infectious diseases is the deployment of hand-held devices at the point-of-care (POC) for screening or self-monitoring applications. There is a need for very sensitive, low-cost and quantitative diagnostic devices. In this study, we present a low-cost, multiplexed fluorescence detection platform that has a high sensitivity and wide dynamic range.

Eccrine Sweat as a Biofluid for Profiling Immune Biomarkers.

Purpose: Sweat is a relatively unexplored biofluid for diagnosis and monitoring of disease states. In this study, the proteomic profiling of immune-related biomarkers from healthy individuals are presented.

Experimental Design: Eccrine sweat samples are collected from 50 healthy individuals.

Design and evaluation of a low cost intracranial pressure monitoring system.

One of the most life-threatening neural conditions is elevated intracranial pressure (ICP); it is associated with ischemia and poor short- and long-term outcomes. Currently, monitoring systems that accurately measure ICP are either highly invasive or inaccurate. This work explores the design and evaluation of an epidural intracranial pressure monitoring system for low-cost, minimally invasive detection.

Application of flat panel OLED display technology for the point-of-care detection of circulating cancer biomarkers.

Point-of-care molecular diagnostics can provide efficient and cost-effective medical care, and they have the potential to fundamentally change our approach to global health. However, most existing approaches are not scalable to include multiple biomarkers. As a solution, we have combined commercial flat panel OLED display technology with protein microarray technology to enable high-density fluorescent, programmable, multiplexed biorecognition in a compact and disposable configuration with clinical-level sensitivity.

A self-powered 2-dimensional motion detection chip.

We demonstrate a self-powered chip to detect motion which enables constant, non-invasive monitoring. The chip was implemented in a standard 0.18 μm CMOS process.

An on-chip system to monitor the pH of cell culture media.

We presents an ion sensitive field effect transistor to measure the pH of the cell culture media of human mammary adenocarcinoma (SKBR3). We use a drift mitigation technique that cycles the transistor to reset the drift in the system. We use to technique in the system to demonstrate an integrated system to monitor the pH continuously.

CMOS self-powered monolithic light-direction sensor with digitalized output.

We present a novel self-powered chip to detect the direction of incident light. This chip directly provides digitized output without the need of any off-chip power supply or optical or mechanical components. The chip was implemented in a standard 0.

Real-time feedback control of pH within microfluidics using integrated sensing and actuation.

We demonstrate a microfluidic system which applies engineering feedback principles to control the pH of a solution with a high degree of precision. The system utilizes an extended-gate ion-sensitive field-effect transistor (ISFET) along with an integrated pseudo-reference electrode to monitor pH values within a microfluidic reaction chamber. The monitored reaction chamber has an approximate volume of 90 nL.

On-chip sensor for light direction detection.

We present an on-chip optical sensor capable of detecting the direction of incident light. No off-chip optical or mechanical components or modifications--for example, baffles, slit structures, mirrors, etc.--are needed.

CMOS biosensor system for on-chip cell culture with read-out circuitry and microfluidic packaging.

A 1.5 mm × 3 mm CMOS chip with sensors for monitoring on-chip cell cultures has been designed. The chip is designed in a 0.

Hybrid silicon/silicone (polydimethylsiloxane) microsystem for cell culture.

We discuss the design, fabrication and testing of a hybrid microsystem for stand-alone cell culture and incubation. The micro-incubator is engineered through the integration of a silicon CMOS die for the heater and temperature sensor, with multilayer silicone PDMS (polydimethylsiloxane) structures namely, fluidic channels and a 4 mm diameter, 30 microL, culture well. A 25 micron thick PDMS membrane covers the top of the culture well, acting as barrier to contaminants while allowing the cells to exchange gases with the ambient environment.