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

BPN873: Small Autonomous Robot Actuator (SARA)

Alex Moreno
Austin Patel
Daniel Teal
Andrew Fearing
2021

The Small Autonomous Robot Actuator (SARA) aims to integrate the Single Chip micro Mote (SCuM), a small millimeter scale solar panel and high voltage buffer (Zappy2), and a MEMS 40-100V inchworm motor that has been demonstrated to push a 7um diameter carbon filament through an adjustable width channel at speeds of 10um/s to 200um/s. SARA has been demonstrated to operate the inchworm motor at 1 Hz with 100V square waves under 200mW/cm2 on separate PCBs and transmit 802.15.4 packets with temperature estimates between 35.5-40 C with a 0.28 std error from SCuM to an OpenMote while on a...

BPN799: 3D Printed Microsensors

Jacqueline Elwood
2021

We aim to develop multi-functional, multi-material 3D printed structures for the development of 3D printed microsensors. Using these multi-functional 3D printed structures, we plan to demonstrate simple sensing platforms, such as EtOH sensing for monitoring of food quality, fermentation, or ethanol content in the body, for proof-of-concept in combining conductive materials with commercially available 3D printing materials or 3D printers. Upon further development, this combination could prove critical in resolving the foremost limitations of conventional diagnostic devices (i.e....

Improved Hydrogen Sensitivity and Selectivity in PdO with Metal-Organic Framework Membrane

David Gardner
Xiang Gao
Hossain M. Fahad
Ali Javey
Carlo Carraro
Roya Maboudian
2020

Metal-organic frameworks (MOFs) are highly designable porous materials and are recognized for their exceptional selectivity as chemical sensors. However, they are not always suitable for incorporation with existing sensing platforms, especially sensing modes that rely on electronic changes in the sensing material (e.g., work-function response or conductometric response). One way that MOFs can be utilized is by growing them as a porous membrane on a sensing layer and using the MOF to affect the electronic structure of the sensing layer. In this paper, a proof-of-concept for...

Transistor‐Based Work Function Measurement of Metal‐Organic Frameworks for Ultra‐Low‐Power, Rationally Designed Chemical Sensors

David Gardner
Xiang Gao
Hossain M. Fahad
An-Ting Yang
Sam He
Ali Javey
Carlo Carraro
Roya Maboudian
2019

A classic challenge in chemical sensing is selectivity. Metal-organic frameworks (MOFs) are an exciting class of materials because they can be tuned for selective chemical adsorption. Adsorption events trigger work-function shifts, which can be detected with a chemical-sensitive field-effect transistor (power ≈microwatts). In this work, several case studies were used towards generalizing the sensing mechanism, ultimately towards our metal-centric hypothesis. HKUST-1 was used as a proof-of-principle humidity sensor. The response is thickness independent, meaning the response is...

Scalable Ultra Low-Power Chemical Sensing with Metal-Organic Frameworks

David Gardner
Xiang Gao
Hossain M. Fahad
An-Ting Yang
Sam He
Ali Javey
Carlo Carraro
Roya Maboudian
2019

This paper reports the innovative use of a highly tunable material, metal-organic frameworks (MOFs), for chemical sensing on an ultra-low-power platform based on a field-effect transistor. We demonstrate proof-of-principle devices functionalized with two MOFs: "HKUST-1" for humidity sensing and "ZIF-8" for reversible NO 2 detection. These devices show minimal drift, yield highly reproducible responses, recover rapidly, and have excellent selectivity. Through this approach, devices with minimal power draw and high selectivity could be widely distributed for continuous environmental and...

Amine-Functionalized Metal-Organic Framework ZIF-8 toward Colorimetric CO2 Sensing in Indoor Air Environment

Adrian K. Davey
Xiang Gao
Yong Xia
Zhou Li
Matthew N. Dods
Steven DelaCruz
Aifei Pan
Sanket Swamy
David Gardner
Carlo Carraro
Roya Maboudian
2021

Carbon dioxide (CO2) has been shown to contribute to human health consequences indoors, such as shortness of breath, nasal and optic irritation, dizziness, and nausea. In this work, we explore the potential of metal–organic frameworks (MOFs) as highly-porous, crystalline sorbents for sensitive colorimetric CO2 detection. In particular, the zeolitic imidazolate framework (ZIF-8) is chosen as the sorptive material due to its chemical stability and tunable CO2 affinity. The colorimetric gas sensor is developed in methanol with three components: (i) MOF ZIF-8 as a high surface area adsorbent...

APP54: MEMS Strain Gauge on Steel: Testing Localized Silicon-Steel Bonds

Theodore Prescop
2003

A rapid bonding process for installing vacuum sealed MEMS strain sensor modules to mechanical components is being developed. This innovative process will be developed to replace conventional adhesive-based approaches. In particular, the silicon to steel bond must achieve these stringent requirements: long life, resistance to chemicals, short bonding process time, and a wide range of storage temperatures. To ensure that the strain within a steel substrate will be accurately measured by the MEMS strain gauge, properties of the bond layer between silicon and steel are observed and...

LWL4: MEMS Sensor for Hard Disk Glide Test

Jongbaeg Kim
2003

Characterization of pitch and roll motions of the slider in the hard disk gimbal system are important parameters in order to achieve higher aerial recording densities. This project describes a novel piezoresistive-type microsensor that could be directly mounted on the existing slider/gimbal system of a hard disk drive to simultaneously measure the pitch and roll angles of the slider.

Project end date: 07/31/03

APP52: MEMS Strain Gauge on Steel: Test Fixture Design

Robert G. Azevedo
2003

The overall project aims to design a MEMS strain gauge that can be bonded directly to steel and accurately measure strain in small strain fields (gauge length of 1 mm or less). In order to verify the group’s designs, I have designed and fabricated a four-point bend test fixture. Strain will be induced in smooth, steel bar stock large enough to allow MEMS and conventional foil strain gauges to be tested simultaneously. The four-point bend test will be used to verify the MEMS strain gauge system-level performance. Further, it will allow comparison of the MEMS gauges to conventional...

BEB6: Electrostatic Actuator Design for a Digital Output Gyroscope

Joseph Seeger
2003

This research investigates the dynamics, design, and control of gap-closing, electrostatic actuators. Because of nonlinearity, gap-closing actuators can give rise to complicated behavior, such as instability, frequency tuning, and parametric resonance. We have demonstrated charge control circuits that stabilize gap-closing actuators and increase the range of motion from 33% of the gap to more than 90% of the gap. We have designed a gyroscope proof-mass with parallel-plate actuators for low voltage oscillation in air with frequency tuning. We have identified parasitic effects, such as...