Michel M. Maharbiz (Advisor)

Research Advised by Professor Michel M. Maharbiz

BPN780: Impedance Spectroscopy to Monitor Fracture Healing

Monica C. Lin

An estimated 15 million fracture injuries occur each year in the United States. Of these, 10% of fractures result in delayed or non-union, with this number rising to 46% when they occur in conjunction with vascular injury. Current methods of monitoring include taking X-rays and making clinical observations. However, radiographic techniques lag and physician examination of injury is fraught with subjectivity. No standardized methods exist to assess the extent of healing that has taken place in a fracture, revealing the need for a diagnostic device that can reliably detect non-union in...

BPN889: Fabrication and Self-Assembly of Microstructured Scaffolds for Living Material

Wei Li

Design, synthesize, assemble, and characterize hard-soft hybrid composites that resemble brick-and- mortar structure of nacre, but that can switch between being porous and flexible to impermeable, stiff, and strong in response to environmental cues.

Project end date: 01/25/19

BPN853: Tethered Bacteria-Based Biosensing

Tom J. Zajdel
Meera Lester

Though the chemotaxis sensing system of emph{Escherichia coli} is known to approach fundamental physical limits for biosensing, few attempts have been made to co-opt the system as the front end for a biohybrid sensor. We propose a biohybrid sensor that monitors chemotactic bacterial flagellar motor (BFM) rotation speed and direction to infer analyte concentration for a low-power, fast, and sensitive response. We present the design and fabrication of a four point impedimetric array that uses current injection electrodes to circumvent electrode polarization screening, enabling solution...

BPN816: Cytokine Fast Detection

Bochao Lu

Sepsis is a life-threatening condition both in civilian and military medical scenarios. Patients with sepsis usually exhibit a vigorous systemic release of cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor (TNF) into serum. The ability to monitor relative cytokine levels continuously at fast time scales (tens of minutes) could open the door to closed-loop, patient-specific sepsis management therapies. The current methods of cytokine detection take hours and cost thousands of dollars because the physiological concentration is so low around...

BPN716: Ultrasonic Wireless Implants for Neuro-Modulation

Konlin Shen
David Piech
Kyoungtae Lee

A major hurdle in brain-machine interfaces (BMI) is the lack of an implantable neural interface system that remains viable for a substantial fraction of a primate lifetime. Recently, sub-mm implantable, wireless electromagnetic (EM) neural interfaces have been demonstrated in an effort to extend system longevity. However, EM systems do not scale down in size well due to the severe inefficiency of coupling radio waves at mm and sub-mm scales. We propose an alternative wireless power...

BPN943: Silicon Carbide Thin Films for Chronically Implanted Microelectronics

Konlin Shen

Chronically implanted integrated circuits (ICs) can enable sophistication in implants beyond purely measurement, such as closed-loop modulation of physiology. However, the body is a corrosive and chemically aggressive environment in which ionic and reactive oxidative species can easily damage implanted microelectronics. Conventionally, implanted ICs are packaged in titanium or ceramic housing to reach decadal lifetime, but such packaging is not conducive to sub-millimeter scale miniaturization. Thin-film encapsulants such as parylene, SiO2, and SiC can greatly...

BPN874: Charge Pumping with Finger Capacitance for Body Energy Harvesting

Alyssa Y. Zhou

Sensors are becoming ubiquitous and increasingly integrated with and on the human body. As these devices grow in number and decrease in size, there grows a critical need to find sustainable and convenient power sources. We demonstrate a touch interrogation powered energy harvesting system which transforms the kinetic energy of a human finger to electric energy. As is well known for touch display devices, the proximity of a finger can alter the effective value of small capacitances, and these capacitance changes can drive a current which is rectified to charge an energy storage...

Rodent Wearable Ultrasound Interrogation System for Wireless Neural Recording

Joshua Kay
Bernhard E. Boser
Michel M. Maharbiz

Advancements in minimally-invasive, distributed biological interface nodes enable possibilities for networks of sensors and actuators to connect the brain with external devices. These brain machine interfacing systems require addressing three critical areas for real world use: signal-acquisition hardware, real-time operation, and long term validation. The recent development of the neural dust sensor mote has shown that utilizing ultrasound backscatter communication enables untethered ...

Light-induced Electrokinetics: A path to a versatile micro total analysis system

Justin K. Valley
Ming C. Wu
Michel M. Maharbiz
Amy E. Herr

The micro total analysis system (μTAS) has seen great interest and advances since its definition over two decades ago. By harnessing the fabrication tools of the semiconductor industry and exploiting the unique physical phenomena that dominate at the micro- to nano-scale,these devices aim to address applications ranging from point-of-care diagnostics to pharmaceutical development. A truly versatile μTAS technology platform will enable reconfigurable, parallel, and high...

Monitoring Deep-Tissue Oxygenation with a Millimeter-Scale Ultrasonic Implant

Soner Sonmezoglu
Jeffrey R. Fineman
Emin Maltepe
Michel M. Maharbiz

Vascular complications following solid organ transplantation may lead to graft ischemia, dysfunction or loss. Imaging approaches can provide intermittent assessments of graft perfusion, but require highly skilled practitioners and do not directly assess graft oxygenation. Existing systems for monitoring tissue oxygenation are limited by the need for wired connections, the inability to provide real-time data or operation restricted to surface tissues. Here, we present a minimally invasive system to monitor deep-tissue O2 that reports continuous real-time data from centimeter-scale depths in...