Physical Sensors & Devices

Research that includes:

  • Silicon MEMS actuators: comb, electro-thermal, and plastic deformation
  • Precision electronic sensing and measurements of capacitive, frequency, and coulombic MEMS variables
  • Structures and architectures for gyroscopes, accelerometers, micro strain gauges for direct application to rigid structures e.g., steel, and levitated MEMS

BPN755: Carrier-Selective Oxide Contacts for Silicon Electronics

Corsin Battaglia
Xingtian Yin
Steven Chuang
Thomas Rembert
Hiroshi Shiraki
2014

Efficient carrier selective contacts are key to electronic devices based on silicon including sensors, microelectromechanical systems, field effect transistors and photovoltaics. We explore substoichiometric molybdenum trioxide (MoOx, x<3) as a dopant-free, hole-selective contact for silicon. As a proof of principle, we demonstrate a silicon solar cell with a MoOx hole contact delivering a high open-circuit voltage of 711 mV and a power conversion efficiency of 18.8%. Due to the wide band gap of MoOx, we observe a substantial gain in photocurrent of 1.9 mA/cm2 in the ultraviolet...

BPN741: Programmable Gyroscope Test Platform

Oleg I. Izyumin
2014

This project aims to develop a compact and self-contained universal test platform for DSP-based control of MEMS gyroscopes and resonant sensors. Many operating modes require features not available in off-the-shelf laboratory instruments, and it is difficult to perform sensor testing and validation with laboratory test equipment due to size and power constraints. We have implemented a multi- channel digital lock-in amplifier in FPGA hardware, providing PLLs, modulators, demodulators, filters, and the capability to add custom functionality. Software-based baseband DSP allows...

BPN726: Transparent Microelectrode Arrays for Hybrid Experiments in Neuroscience

Brian Pepin
2014

Optogenetics techniques that have been developed over the previous decade allow cell-type specific optical stimulation of neurons in-vivo. However, it remains a challenge to perform simultaneous electrical recording while providing optical stimulation due to photoelectric artifact generated at the microelectrode recording sites. This project aims to address this challenge by developing bio- compatible microelectrode arrays with optically transparent recording sites. Current devices are optimized for performing electrocorticography (ECoG) experiments and use Indium-Tin Oxide (ITO, a...

BPN708: Direct-Write Graphene Channel Field Effect with Self-Aligned Top Gate

Yumeng Liu
2014

The project amis at using Near Field Electrospinnin to fabricate top gate graphene transistor that is capable to pattern the source and drain electrodes through a self-alignment process, and the long range goals is to direct writing graphene transistors onto flexible and transparent substrate for low cost circuit applications, say RF mixer. As the conventional top gated device fabrication process often introduces the deposition of thin inorganic dielectric onto graphene layer with extra surface functionalizations, leading to an undesired damage of graphene lattice, or a non-ideal...

BPN687: Robust Optical Flame Detection in Harsh Environments

Kaiyuan Yao
2014

The goal of this project is to create a UV sensor for use as a flame detection system in gas turbine engine applications. In many gas-turbine engines, unnecessary engine shutdowns arise from sensors failing to detect the engine flame because of deep films of oil and/or water that block the sensor. In the infrared- and visible-light regions of the optical spectrum there is limited penetration through oil/water mixtures. A UV sensor is to be designed that will be able to robustly detect flames through oil/water mixtures that may build up on lenses in the gas turbine engine. For this...

BPN763: Surface Acoustic Wave-Based Sensors for Harsh Environment Applications

Shuo Chen
2014

Sensing in harsh environment, especially high temperature environment, is drawing more attention, with potential applications in energy sector. The motivations are that enhanced (pressure, temperature, chemical) sensing will allow more efficient operation, enabling condition- based monitoring and reducing unwanted emission. State-of-the-art sensing technology remains limited, either not capable of long-term online monitoring under high temperature due to materials failure or, occupying too much space. We propose to adapt MEMS fabrication process and concepts to our proposed research...

BPN505: Deployment of Wireless Stick-On Circuit Breaker PEM AC Sensors for the Smart Grid

Richard Xu
2014

The electric power consumption of the entire Berkeley campus ranges from 18MW to 30MW,of which Cory Hall, the Electrical Engineering building, comprises from 3% to 5%. Presently, the power entering the building is metered monthly at the primary terminals of its 12.4 kilovolt distribution step-down transformer. In order to increase energy efficiency and to experiment with, and further develop, our miniature electrical sensors, we are in the process of installing proximity sub-metering of loads accessed through a standard circuit breaker panel to which miniature proximity-based current...

BPN705: Standard CMOS-Based, Fully Integrated, Stick-On Electricity Meters for Building Sub-Metering

Michael C. Lorek
2015

We propose the development and testing of a system of technologies to minimize the installed cost of electricity sub-metering in buildings. This system utilizes non-contact, self-calibrating voltage and current sensors and wireless communication to eliminate the need for installation by an electrician, installation of conduit and enclosures, and installation of wired communication infrastructure. Electricity sub-metering is a critical component for continuous commissioning, fault detection and diagnosis, demand response, and other energy efficiency opportunities.

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BPN764: Untethered Stress-Engineered MEMS MicroFlyers

Spencer Ward
Ameen Hussain
Vahid Foroutan
Ratul Majumdar
2015

In this project, we are developing and testing microscale flying structures, called Microflyers. The microflyers consist of a 300 µm × 300 µm sized chassis fabricated from polycrystalline silicon using surface micromachining. At present, the flyers are levitated using microfabricated heaters attached to an underlying substrate. A novel, in-situ masked post-release stress-engineering process is used to generate a concave upwards curvature of the flyers chassis, causing static pitch and roll stability during flight, take-off, and landing. The initial experiments have demonstrated...

BPN768: Plug-Through Energy Monitor for Wall Outlet Electrical Devices

Michael C. Lorek
2015

This project focuses on the development of a Plug-Through Energy Monitor (PTEM) for electrical devices connected to wall outlets. Using a non-intrusive inductive current sensing technique, the load current can be measured without requiring a series sensing element that breaks the circuit. This enables slim profile sensing hardware, and eliminates the power dissipated across series elements as in traditional current measurement techniques. This work aims to design a PCB-based solution that measures load current & line voltage, accurately calculates real power dissipated by a plug...