Nathan Jackson | University of New Mexico (original) (raw)

Papers by Nathan Jackson

Micromachines, May 15, 2020

Sensors and Actuators A-physical, Aug 1, 2016

Abstract Vibration energy harvesters typically have a narrow bandwidth, which allows them to gene... more Abstract Vibration energy harvesters typically have a narrow bandwidth, which allows them to generate high amounts of power, but only at a specific frequency. This paper presents a novel method of increasing the bandwidth of a cantilever beam by creating a non-uniform load. The concept uses a liquid filled mass, which causes the structures overall centre of gravity to shift as the beam bends. The overall centre of gravity shifts due to the mass change caused by the dynamic behaviour of the fluid. This paper validates the concept both numerically and experimentally by using a custom manufactured fluid filled mass on a piezoelectric cantilever. A water filled mass demonstrated a 2.8x increase in bandwidth for low acceleration (

ABSTRACT A COMSOL MultiphysicsR model was created which provides accurate information on the reso... more ABSTRACT A COMSOL MultiphysicsR model was created which provides accurate information on the resonant frequency, stress and power output of an ALN piezoelectric device. The maximum error in the resonant frequency was found to be 4%. The models accurately predicted the trend of the output power for external impedances as well as the matched impedance for maximum energy harvesting. The expected voltage and current output for 1g acceleration was also be modeled.

Journal of Applied Polymer Science, Nov 1, 2014

ABSTRACTElectro‐responsive hydrogels (ERH) are highly researched materials for biomedical applica... more ABSTRACTElectro‐responsive hydrogels (ERH) are highly researched materials for biomedical applications. However, most of the research is concentrated on the synthesis of novel hydrogels for various applications, and little effort has been made to investigate electrode configuration and optimization of electrical stimulation parameters. This article used a three‐dimensional interdigitated (IDT) electrode configuration device to investigate the optimization of electrical actuation parameters in order to radially deswell an ERH. A Pluronic‐bismethacrylate hydrogel modified with hydrolyzed methacrylic acid was used as the ERH material. This article reports on using novel electro‐actuation parameters and electrode configurations to maximize radial deswelling of an ERH for biomedical applications. The optimal waveform was assessed for, varying electrode spacing's, voltages, duty cycles, and frequencies. The results show that a maximum deswelling occurred with a DC pulsed monophasic waveform, with IDT electrodes spaced close enough to create a relatively uniform electric field, with a peak voltage of 5 V at 1 kHz, and 50% duty cycle. This resulted in a deswelling of 320% in Krebs solution. Electrochemical impedance spectroscopy results show that the impedance is dependent on the ionic concentration of the fluid environment and that the impedance decreases with increasing frequency. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41687.

Sensors and Actuators A-physical, Dec 1, 2018

Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, Nov 27, 2018

ABSTRACT Cardiovascular disease affects millions of patients every year worldwide. Electroactive ... more ABSTRACT Cardiovascular disease affects millions of patients every year worldwide. Electroactive hydrogel polymers have the ability to swell or shrink in a fluid environment, which makes them an ideal candidate for preventing blood flow through blood vessels. The authors present preliminary reliability testing results of the long-term use of implanted EAP hydrogel material for intravascular applications. Mechanical testing was performed to determine the Young’s modulus and the pressure threshold to cause failure of the material in DI and Krebs solution. Accelerated testing was performed at elevated temperatures to determine the mean-time-to-failure using an Arrhenius model. The affects of various sized proteins on the EAP hydrogel were also investigated with and without electrical bias. An artificial circulation setup with mock blood vessels was used to determine the optimal dimensions of the EAP hydrogel material to prevent blood flow and the required minimum pressure to cause failure. The outcome of this study enables researchers to design EAP hydrogels with greater reliability and optimal shapes.

ABSTRACT The increasing importance of autonomous devices has focused on strategies of energy harv... more ABSTRACT The increasing importance of autonomous devices has focused on strategies of energy harvesting in order to provide the required energy for these kinds of applications. One of the possibilities to develop energy harvesting is through piezoelectric materials which can convert mechanical vibrations into electrical energy. An examination of finite element modeling of cantilever beams is discussed here and the advantages and future possibilities for fabrication are investigated. This paper highlights how researchers can create different shapes or fabrication techniques to optimize the resonant frequency based on finite element modeling.

IEEE Transactions on Biomedical Engineering, Feb 1, 2015

Thin Solid Films, Mar 1, 2016

Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, Dec 5, 2013

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

High Q-Factor vibrational energy harvesters are ideal as they maximize power generation, but a na... more High Q-Factor vibrational energy harvesters are ideal as they maximize power generation, but a narrow bandwidth limits the potential use in most commercial applications, and it is a major challenge that has not been resolved. Numerous designs have been investigated to solve this challenge but most of the attempts are based on frequency sweeping mechanism or require complex design/fabrication which are not practical especially for MEMS devices. This paper reports for the first time a transverse vertical moving mass inside the proof mass as a method to widen the bandwidth which is independent of frequency sweeping. The out-of-plane movable mass is achieved by fabricating a vertical cavity in the proof mass and partially filling the cavity with metallic spheres. Ultra-wide bandwidth was achieved for low (0.5g) and high (1g) accelerations with an increase in bandwidth from 3.9 Hz (control) to 56 Hz (movable mass). This transverse method of widening the bandwidth is potentially scalable ...

ECS Meeting Abstracts, 2020

SPIE Proceedings, 2017

Biomimetic micro-robots try to mimic the motion of a living system in the form of a synthetically... more Biomimetic micro-robots try to mimic the motion of a living system in the form of a synthetically developed microfabricated device. Dynamic motion of living systems have evolved through the years, but trying to mimic these motions is challenging. Micro-robotics are particular challenging as the fabrication of devices and controlling the motion in 3 dimensions is difficult. However, micro-scale robotics have potential to be used in a wide range of applications. MEMS based robots that can move and function in a liquid environment is of particular interest. This paper describes the development of a piezoMEMS based device that mimics the movement of a jellyfish. The paper focuses on the development of a finite element model that investigates a method of controlling the individual piezoelectric beams in order to create a jet propulsion motion, consisting of a quick excitation pulse followed by a slow recovery pulse in order to maximize thrust and velocity. By controlling the individual beams or legs of the jellyfish robot the authors can control the robot to move precisely in 3 dimensions.

Journal of Dispersion Science and Technology, 2017

Sensors and Actuators A: Physical, 2016