228 research outputs found
Surgical Instruments based on flexible micro-electronics
This dissertation explores strategies to create micro-scale tools with integrated electronic and mechanical functionalities. Recently developed approaches to control the shape of flexible micro-structures are employed to fabricate micro-electronic instruments that embed components for sensing and actuation, aiming to expand the toolkit of minimally invasive surgery. This thesis proposes two distinct types of devices that might expand the boundaries of modern surgical interventions and enable new bio-medical applications.
First, an electronically integrated micro-catheter is developed. Electronic components for sensing and actuation are embedded into the catheter wall through an alternative fabrication paradigm that takes advantage of a self-rolling polymeric thin-film system. With a diameter of only 0.1 mm, the catheter is capable of delivering fluids in a highly targeted fashion, comprises actuated opposing digits for the efficient manipulation of microscopic objects, and a magnetic sensor for navigation. Employing a specially conceived approach for position tracking, navigation with a high resolution below 0.1 mm is achieved. The fundamental functionalities and mechanical properties of this instrument are evaluated in artificial model environments and ex vivo tissues. The second development explores reshapeable micro-electronic devices. These systems integrate conductive polymer actuators and strain or magnetic sensors to adjust their shape through feedback-driven closed loop control and mechanically interact with their environment. Due to their inherent flexibility and integrated sensory capabilities, these devices are well suited to interface with and manipulate sensitive biological tissues, as demonstrated with an ex vivo nerve bundle, and may facilitate new interventions in neural surgery.:List of Abbreviations
1 Introduction
1.1 Motivation
1.2 Objectives and structure of this dissertation
2 Background
2.1 Tools for minimally invasive surgery
2.1.1 Catheters
2.1.2 Tools for robotic micro-surgery
2.1.3 Flexible electronics for smart surgical tools
2.2 Platforms for shapeable electronics
2.2.1 Shapeable polymer composites
2.2.2 Shapeable electronics
2.2.3 Soft actuators and manipulators
2.3 Sensors for position and shape feedback
2.3.1 Magnetic sensors for position and orientation measurements
2.3.2 Strain gauge sensors
3 Materials and Methods
3.1 Materials for shapeable electronics
3.1.1 Metal-organic sacrificial layer
3.1.2 Polyimide as reinforcing material
3.1.3 Swelling hydrogel for self assembly
3.1.4 Polypyrrole for flexible micro actuators
3.2 Device fabrication techniques
3.2.1 Photolithography
3.2.2 Electron beam deposition
3.2.3 Sputter deposition
3.2.4 Atomic layer deposition
3.2.5 Electro-polymerization of polypyrrole
3.3 Device characterization techniques
3.3.1 Kerr magnetometry
3.3.2 Electro-magnetic characterization of sensors
3.3.3 Electro-chemical analysis of polypyrrole
3.3.4 Preparation of model environments and materials
3.4 Sensor signal evaluation and processing
3.4.1 Signal processing
3.4.2 Cross correlation for phase analysis
3.4.3 PID feedback control
4 Electronically Integrated Self Assembled Micro Catheters
4.1 Design and Fabrication
4.1.1 Fabrication and self assembly
4.1.2 Features and design considerations
4.1.3 Electronic and fluidic connections
4.2 Integrated features and functionalities
4.2.1 Fluidic transport
4.2.2 Bending stability
4.2.3 Actuated micro manipulator
4.3 Magnetic position tracking
4.3.1 Integrated magnetic sensor
4.3.2 Position control with sensor feedback
4.3.3 Introduction of magnetic phase encoded tracking
4.3.4 Experimental realization
4.3.5 Simultaneous magnetic and ultrasound tracking
4.3.6 Discussion, limitations, and perspectives
5 Reshapeable Micro Electronic Devices
5.1 Design and fabrication
5.1.1 Estimation of optimal fabrication parameters
5.1.2 Device Fabrication
5.1.3 Control electronics and software
5.2 Performance of Actuators
5.2.1 Blocking force, speed, and durability
5.2.2 Curvature
5.3 Orientation control with magnetic sensors
5.3.1 Magnetic sensors on actuated device
5.3.2 Reference magnetic field
5.3.3 Feedback control
5.4 Shape control with integrated strain sensors
5.4.1 Strain gauge curvature sensors
5.4.2 Feedback control
5.4.3 Obstacle detection
5.5 Heterogenous integration with active electronics
5.5.1 Fabrication and properties of active matrices
5.5.2 Fabrication and operation of PPy actuators
5.5.3 Site selective actuation
6 Discussion and Outlook
6.1 Integrated self assembled catheters
6.1.1 Outlook
6.2 Reshapeable micro electronic devices
6.2.1 Outlook
7 Conclusion
Appendix
A1 Processing parameters for polymer stack layers
A2 Derivation of magnetic phase profile in 3D
Bibliography
List of Figures and Tables
Acknowledgements
Theses
List of Publication
Computational fluid dynamics modeling and in situ physics-based monitoring of aerosol jet printing toward functional assurance of additively-manufactured, flexible and hybrid electronics
Aerosol jet printing (AJP)—a direct-write, additive manufacturing technique—has emerged as the process of choice particularly for the fabrication of flexible and hybrid electronics. AJP has paved the way for high-resolution device fabrication with high placement accuracy, edge definition, and adhesion. In addition, AJP accommodates a broad range of ink viscosity, and allows for printing on non-planer surfaces. Despite the unique advantages and host of strategic applications, AJP is a highly unstable and complex process, prone to gradual drifts in machine behavior and deposited material. Hence, real-time monitoring and control of AJP process is a burgeoning need. In pursuit of this goal, the objectives of the work are, as follows: (i) In situ image acquisition from the traces/lines of printed electronic devices right after deposition. To realize this objective, the AJP experimental setup was instrumented with a high-resolution charge-coupled device (CCD) camera, mounted on a variable-magnification lens (in addition to the standard imaging system, already installed on the AJ printer). (ii) In situ image processing and quantification of the trace morphology. In this regard, several customized image processing algorithms were devised to quantify/extract various aspects of the trace morphology from online images. In addition, based on the concept of shape-from-shading (SfS), several other algorithms were introduced, allowing for not only reconstruction of the 3D profile of the AJ-printed electronic traces, but also quantification of 3D morphology traits, such as thickness, cross-sectional area, and surface roughness, among others. (iii) Development of a supervised multiple-input, single-output (MISO) machine learning model—based on sparse representation for classification (SRC)—with the aim to estimate the device functional properties (e.g., resistance) in near real-time with an accuracy of ≥ 90%. (iv) Forwarding a computational fluid dynamics (CFD) model to explain the underlying aerodynamic phenomena behind aerosol transport and deposition in AJP process, observed experimentally.
Overall, this doctoral dissertation paves the way for: (i) implementation of physics-based real-time monitoring and control of AJP process toward conformal material deposition and device fabrication; and (ii) optimal design of direct-write components, such as nozzles, deposition heads, virtual impactors, atomizers, etc
Design, characterization and validation of integrated bioelectronics for cellular studies: from inkjet-printed sensors to organic actuators
Mención Internacional en el título de doctorAdvances in bioinspired and biomimetic electronics have enabled
coupling engineering devices to biological systems with unprecedented
integration levels. Major efforts, however, have been devoted to interface
malleable electronic devices externally to the organs and tissues. A promising
alternative is embedding electronics into living tissues/organs or,
turning the concept inside out, lading electronic devices with soft living
matters which may accomplish remote monitoring and control of tissue’s
functions from within. This endeavor may unleash the ability to engineer
“living electronics” for regenerative medicine and biomedical applications.
In this context, it remains a challenge to insert electronic devices efficiently
with living cells in a way that there are minimal adverse reactions
in the biological host while the electronics maintaining the engineered
functionalities. In addition, investigating in real-time and with minimal
invasion the long-term responses of biological systems that are brought
in contact with such bioelectronic devices is desirable.
In this work we introduce the development (design, fabrication and
characterization) and validation of sensors and actuators mechanically
soft and compliant to cells able to properly operate embedded into a
cell culture environment, specifically of a cell line of human epithelial
keratinocytes. For the development of the sensors we propose moving from conventional microtechnology approaches to techniques compatible
with bioprinting in a way to support the eventual fabrication of tissues
and electronic sensors in a single hybrid plataform simultaneously. For
the actuators we explore the use of electroactive, organic, printing-compatible
polymers to induce cellular responses as a drug-free alternative
to the classic chemical route in a way to gain eventual control of biological
behaviors electronically. In particular, the presented work introduces
inkjet-printed interdigitated electrodes to monitor label-freely and
non-invasively cellular migration, proliferation and cell-sensor adhesions
of epidermal cells (HaCaT cells) using impedance spectroscopy and the
effects of (dynamic) mechanical stimulation on proliferation, migration
and morphology of keratinocytes by varying the magnitude, frequency
and duration of mechanical stimuli exploiting the developed biocompatible
actuator.
The results of this thesis contribute to the envision of three-dimensional
laboratory-growth tissues with built-in electronics, paving exciting
avenues towards the idea of living smart cyborg-skin substitutes.En los útimos años los avances en el desarrollo de dispositivos
electrónicos diseñados imitando las propiedades de sistemas vivos han
logrado acoplar sistemas electrónicos y órganos/tejidos biológicos con
un nivel de integración sin precedentes. Convencionalmente, la forma
en que estos sistemas bioelectrónicos son integrados con órganos o tejidos
ha sido a través del contacto superficial entre ambos sistemas, es
decir acoplando la electrónica externamente al tejido. Lamentablemente
estas aproximaciones no contemplan escenarios donde ha habido una
pérdida o daño del tejido con el cual interactuar, como es el caso de daños
en la piel debido a quemaduras, úlceras u otras lesiones genéticas
o producidas. Una alternativa prometedora para ingeniería de tejidos y
medicina regenerativa, y en particular para implantes de piel, es embeber
la electrónica dentro del tejido, o presentado de otra manera, cargar
el sistema electrónico con células vivas y tejidos fabricados por ingeniería
de tejidos como parte innata del propio dispositivo. Este concepto
permitiría no solo una monitorización remota y un control basado en
señalizaciones eléctricas (sin químicos) de tejidos biológicos fabricados
mediante técnicas de bioingeniería desde dentro del propio tejido, sino
también la fabricación de una “electrónica viva”, biológica y eléctricamente
funcional. En este contexto, es un desafío insertar de manera
eficiente dispositivos electrónicos con células vivas sin desencadenar
reacciones adversas en el sistema biológico receptor ni en el sistema
electrónico diseñado. Además, es deseable monitorizar en tiempo real
y de manera mínimamente invasiva las respuestas de dichos sistemas
biológicos que se han añadido a tales dispositivos bioelectrónicos.
En este trabajo presentamos el desarrollo (diseño, fabricación y caracterización)
y validación de sensores y actuadores mecánicamente suaves y
compatibles con células capaces de funcionar correctamente dentro de un
entorno de cultivo celular, específicamente de una línea celular de células epiteliales
humanas. Para el desarrollo de los sensores hemos propuesto utilizar
técnicas compatibles con la bioimpresión, alejándonos de la micro fabricación
tradicionalmente usada para la manufactura de sensores electrónicos, con el
objetivo a largo plazo de promover la fabricación de los tejidos y los sensores
electrónicos simultáneamente en un mismo sistema de impresión híbrido.
Para el desarrollo de los actuadores hemos explorado el uso de polímeros
electroactivos y compatibles con impresión y hemos investigado el efecto
de estímulos mecánicos dinámicos en respuestas celulares con el objetivo a
largo plazo de autoinducir comportamientos biológicos controlados de forma
electrónica. En concreto, este trabajo presenta sensores basados en electrodos
interdigitados impresos por inyección de tinta para monitorear la migración
celular, proliferación y adhesiones célula-sustrato de una línea celular de
células epiteliales humanas (HaCaT) en tiempo real y de manera no invasiva
mediante espectroscopía de impedancia. Por otro lado, este trabajo presenta
actuadores biocompatibles basados en el polímero piezoeléctrico fluoruro de
poli vinilideno y ha investigado los efectos de estimular mecánicamente células
epiteliales en relación con la proliferación, migración y morfología celular
mediante variaciones dinámicas de la magnitud, frecuencia y duración de
estímulos mecánicos explotando el actuador biocompatible propuesto.
Ambos sistemas presentados como resultado de esta tesis doctoral
contribuyen al desarrollo de tejidos 3D con electrónica incorporada,
promoviendo una investigación hacia la fabricación de sustitutos equivalentes
de piel mitad orgánica mitad electrónica como tejidos funcionales
biónicos inteligentes.The main works presented in this thesis have been
conducted in the facilities of the Universidad Carlos III
de Madrid with support from the program Formación del
Profesorado Universitario FPU015/06208 granted by Spanish Ministry
of Education, Culture and Sports. Some of the work has been also
developed in the facilities of the Fraunhofer-Institut für Zuverlässigkeit
und Mikrointegration (IZM) and University of Applied Sciences (HTW) in
Berlin, under the supervision of Prof. Dr. Ing. H-D. Ngo during a research
visit funded by the Mobility Fellows Program by the Spanish Ministry of
Education, Culture, and Sports.
This work has been developed in the framework of the projects
BIOPIELTEC-CM (P2018/BAA-4480), funded by Comunidad de Madrid,
and PARAQUA (TEC2017-86271-R) funded by Ministerio de Ciencia e
Innovación.Programa de Doctorado en Ingeniería Eléctrica, Electrónica y Automática por la Universidad Carlos III de MadridPresidente: José Antonio García Souto.- Secretario: Carlos Elvira Pujalte.- Vocal: María Dimak
Adaptive Multi-Functional Space Systems for Micro-Climate Control
This report summarizes the work done during the Adaptive Multifunctional Systems for Microclimate
Control Study held at the Caltech Keck Institute for Space Studies (KISS) in 2014-2015.
Dr. Marco Quadrelli (JPL), Dr. James Lyke (AFRL), and Prof. Sergio Pellegrino (Caltech) led
the Study, which included two workshops: the first in May of 2014, and another in February
of 2015. The Final Report of the Study presented here describes the potential relevance of
adaptive multifunctional systems for microclimate control to the missions outlined in the 2010
NRC Decadal Survey.
The objective of the Study was to adapt the most recent advances in multifunctional reconfigurable
and adaptive structures to enable a microenvironment control to support space exploration in
extreme environments (EE). The technical goal was to identify the most efficient materials,
architectures, structures and means of deployment/reconfiguration, system autonomy and energy
management solutions needed to optimally project/generate a micro-environment around space
assets. For example, compact packed thin-layer reflective structures unfolding to large areas
can reflect solar energy, warming and illuminating assets such as exploration rovers on Mars or
human habitats on the Moon. This novel solution is called an energy-projecting multifunctional
system (EPMFS), which are composed of Multifunctional Systems (MFS) and Energy-Projecting
Systems (EPS)
Mechatronic Systems
Mechatronics, the synergistic blend of mechanics, electronics, and computer science, has evolved over the past twenty five years, leading to a novel stage of engineering design. By integrating the best design practices with the most advanced technologies, mechatronics aims at realizing high-quality products, guaranteeing at the same time a substantial reduction of time and costs of manufacturing. Mechatronic systems are manifold and range from machine components, motion generators, and power producing machines to more complex devices, such as robotic systems and transportation vehicles. With its twenty chapters, which collect contributions from many researchers worldwide, this book provides an excellent survey of recent work in the field of mechatronics with applications in various fields, like robotics, medical and assistive technology, human-machine interaction, unmanned vehicles, manufacturing, and education. We would like to thank all the authors who have invested a great deal of time to write such interesting chapters, which we are sure will be valuable to the readers. Chapters 1 to 6 deal with applications of mechatronics for the development of robotic systems. Medical and assistive technologies and human-machine interaction systems are the topic of chapters 7 to 13.Chapters 14 and 15 concern mechatronic systems for autonomous vehicles. Chapters 16-19 deal with mechatronics in manufacturing contexts. Chapter 20 concludes the book, describing a method for the installation of mechatronics education in schools
Wireless Communication System for Submucosal Implants
Refluxní choroba jícnu (GERD) a gastroparéza jsou dvě nemoci gastrointestinálního traktu (GIT), které můžou být charakterizovány nedostatečnou funkcí příslušné svaloviny. U refluxní choroby jícnu nedochází k uzávěru dolnojícnového svěrače, což umožňuje vstup kyselého obsahu žaludku do jícnu. Gastroparéza je charakteristická částečnou paralýzou žaludku, což vede k tomu, že potrava v něm zůstává po dobu delší, než je běžné. Léčba těchto onemocnění je zpravidla medikamentózní nebo chirurgická, která s sebou nese zvýšená rizika. Endoskopie zažívá v posledních letech zvýšený zájem, protože se jedná o téměř neinvazivní techniku pro zákroky v GIT. Cilem této diplomové práce je vývoj bezdrátového rozhraní pro aktivní implantabilní zdravotnický prostředek (AIMD), který by mohl být použit pro léčbu GERD a gastroparézy. Zařízení je implantováno technikou, která se nazývá "endoscopic submucosal pocketing". Práce je specificky zaměřena na vývoj bezdrátového komunikačního rozhraní provozovaného v pásmu MEDS. Konvoluční kodování a šifrování je vyvinuto a implementováno. Prototyp AIMD s biokompatibilním obalem a zařízením pro příjem dat a nabíjením bylo vyvinuto a navržený obousměrný bezdrátový komunikační řetězec byl implementován v jazyce C s použitím mikrokontrolerů PIC a Si4455 radiového transceiveru. Nakonec bylo zařízení otestováno jeho implantací do submukozy v prasečím žaludku pomocí endoskopu, čímž byla otestována možnost jeho využití v navazujícím výzkumu.Gastroesophageal reflux disease (GERD) and gastroparesis are two diseases of gastrointestinal tract (GIT) which can be characterized by the disorder of muscle tissue. In GERD, the lower esophageal sphincter does not close properly, allowing the acidic contents of stomach to enter esophagus. Gastroparesis is characterized by partial paralysis of stomach, resulting in food remaining there for an abnormally long time. Treatment for these diseases includes medication and invasive surgery which is dangerous. In recent years, endoscopy is getting attention because it is virtually non-invasive technique for surgeries inside GIT. The goal of this thesis is the development of wireless link for an active implantable medical device (AIMD) which could be used in treatment of GERD and gastroparesis. The device is implanted using a technique called endoscopic submucosal pocketing. Focus is given to the design of the wireless communication link which is operated in MEDS band. Convolutional coding and encryption is developed and implemented in the system. A prototype of AIMD with biocompatible housing and a receiver/charger device was developed and the proposed bidirectional wireless communication link was implemented using C language, PIC microcontrollers and Si4455 radio transceivers. Finally, the device was implanted into submucosa of a pig stomach with an endoscope to test the feasibility of using the device during ongoing research
Integrated Circuits/Microchips
With the world marching inexorably towards the fourth industrial revolution (IR 4.0), one is now embracing lives with artificial intelligence (AI), the Internet of Things (IoTs), virtual reality (VR) and 5G technology. Wherever we are, whatever we are doing, there are electronic devices that we rely indispensably on. While some of these technologies, such as those fueled with smart, autonomous systems, are seemingly precocious; others have existed for quite a while. These devices range from simple home appliances, entertainment media to complex aeronautical instruments. Clearly, the daily lives of mankind today are interwoven seamlessly with electronics. Surprising as it may seem, the cornerstone that empowers these electronic devices is nothing more than a mere diminutive semiconductor cube block. More colloquially referred to as the Very-Large-Scale-Integration (VLSI) chip or an integrated circuit (IC) chip or simply a microchip, this semiconductor cube block, approximately the size of a grain of rice, is composed of millions to billions of transistors. The transistors are interconnected in such a way that allows electrical circuitries for certain applications to be realized. Some of these chips serve specific permanent applications and are known as Application Specific Integrated Circuits (ASICS); while, others are computing processors which could be programmed for diverse applications. The computer processor, together with its supporting hardware and user interfaces, is known as an embedded system.In this book, a variety of topics related to microchips are extensively illustrated. The topics encompass the physics of the microchip device, as well as its design methods and applications
Electronic systems for the restoration of the sense of touch in upper limb prosthetics
In the last few years, research on active prosthetics for upper limbs focused
on improving the human functionalities and the control. New methods have
been proposed for measuring the user muscle activity and translating it into
the prosthesis control commands. Developing the feed-forward interface so
that the prosthesis better follows the intention of the user is an important
step towards improving the quality of life of people with limb amputation.
However, prosthesis users can neither feel if something or someone is
touching them over the prosthesis and nor perceive the temperature or
roughness of objects. Prosthesis users are helped by looking at an object,
but they cannot detect anything otherwise. Their sight gives them most
information. Therefore, to foster the prosthesis embodiment and utility,
it is necessary to have a prosthetic system that not only responds to the
control signals provided by the user, but also transmits back to the user
the information about the current state of the prosthesis.
This thesis presents an electronic skin system to close the loop in prostheses
towards the restoration of the sense of touch in prosthesis users. The
proposed electronic skin system inlcudes an advanced distributed sensing
(electronic skin), a system for (i) signal conditioning, (ii) data acquisition,
and (iii) data processing, and a stimulation system. The idea is to integrate
all these components into a myoelectric prosthesis.
Embedding the electronic system and the sensing materials is a critical issue
on the way of development of new prostheses. In particular, processing
the data, originated from the electronic skin, into low- or high-level information
is the key issue to be addressed by the embedded electronic system.
Recently, it has been proved that the Machine Learning is a promising
approach in processing tactile sensors information. Many studies have
been shown the Machine Learning eectiveness in the classication of input
touch modalities.More specically, this thesis is focused on the stimulation system, allowing
the communication of a mechanical interaction from the electronic skin
to prosthesis users, and the dedicated implementation of algorithms for
processing tactile data originating from the electronic skin. On system
level, the thesis provides design of the experimental setup, experimental
protocol, and of algorithms to process tactile data. On architectural level,
the thesis proposes a design
ow for the implementation of digital circuits
for both FPGA and integrated circuits, and techniques for the power
management of embedded systems for Machine Learning algorithms
Cutting Edge Nanotechnology
The main purpose of this book is to describe important issues in various types of devices ranging from conventional transistors (opening chapters of the book) to molecular electronic devices whose fabrication and operation is discussed in the last few chapters of the book. As such, this book can serve as a guide for identifications of important areas of research in micro, nano and molecular electronics. We deeply acknowledge valuable contributions that each of the authors made in writing these excellent chapters
Organic thin film transistors: integration challenges
This thesis considers some of the requirements and challenges in the eld of organic thin lm transistors (OTFTs), from the standpoint of large scale integration using low temperature plastic compatible processes. A combination of processes and materials for use in the fabrication of OTFTs is developed, yielding device performance comparable with the state of the art for bottom-contact, bottom-gate, organic small molecule thin lm transistors. High quality silicon nitride (SiNx) gate dielectric material is developed using plasma enhanced chemical vapour deposition (PECVD) at a low temperature (150 C) compatible with plastic substrates. A variety of high quality lms are developed, allowing an investigation into the impact of changes in SiNx composition on OTFT performance. Surface modi cation strategies on SiNx substrates are considered, leading to almost an order of magnitude enhancement in OTFT performance, suggesting a suitable device architecture for large scale integration, and exploitation of novel organic material properties. We then examine organic semiconductor nanowire devices, which have begun to emerge as a new and exciting class of device in recent years. This work explores the possibilities of combining traditional thin lm transistor fabrication techniques with novel organic nanowires and examines the resultant transistor device behaviour. Two-dimensional arrays of nanowire devices are analysed, demonstrating the suitability of devices for large area applications. The combination of a large area and plastic compatible, low temperature dielectric with well known organic semiconductors in thin lm devices suggests that the integration of novel organic nanowires could provide an exciting performance enhancement over traditional OTFT devices
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