Energy Harvesting for Pacemakers: Combining Cardiac Measurement Techniques to Improve Testing

A pacemaker runs on a conventional battery that lasts for approximately 6-12 years, after which the pacemaker must be replaced. Converting the heart wall vibrations into electricity through a vibration energy harvester has been considered a promising solution to this problem. However, the complexity of the heart signals on which the energy...

Compliant Remote-Center-of-Motion Mechanism Optimized for Energy-Dispersive Spectroscopy

In-situ sample holders with double-tilting capabilities are used to insert and position samples inside a transmission electron microscope for dynamic imaging. However, the performance of these sample holders, regarding energy-dispersive X-ray spectroscopy (EDS) analysis, is not on par with their single-tilt counterparts. By analyzing the EDS...

Design of a bistable stapes prosthesis

Otosclerosis is a bone disease of the middle ear that often causes conductive hearing loss. This type of hearing loss can be treated by implanting a prosthesis, which replaces the stapes bone and attaches to the adjacent bone: the incus. Current stapes prostheses produce excellent hearing results, however the procedure is difficult to perform...

Vibration Energy Harvesting from Human Motion: by Frequency up-conversion through Impact

Vibration Energy Harvesting has the potential to become a convenient, sustainable and localized power source for the billions of small electronic devices of the future. One of the most challenging areas within this field is the design of miniaturized generators for power harvesting from human motion. In this thesis, a new strategy, design and...

Parameter study of velocity damped vibration energy harvesters

Existing research on vibration energy harvesting is often limited to two-parameter optimizations and single-frequency operation. In this paper a parameter study is performed on the four major design parameters of velocity-damped vibration energy harvesters in low frequency and wide bandwidth operation. The study is based on electromagnetic...

A Compliant Constant Energy Mechanism

In the thesis a Compliant Constant Energy Mechanism(CCEM) has been designed which converts a variable input torque to a constant output torque. A compliant mechanism functions by exploiting the natural elasticity of a material, rather than avoiding it. This allows for the CCEM to have its functionality integrated in to a single part and makes it...

Monolithic Piezoelectric Vibration Energy Harvesting: for low frequency and wide bandwidth operation

Energy harvesting is the process by which energy is derived from environmental vibrations in order to power local electronic systems . The technology gets rid of the need for electrical wires or batteries in a wide range of sensor and communication networks. This work tackles the three most challenging aspects in the field of vibration energy...

Compliant Continuous-Locking Micro Mechanism: Design of a Locking Mechanism for Frequency Tuning

Micro-electromechanical systems (MEMS) often require tuning to correct for fabrication errors such as changed dimensions or to adapt for a different scenario such as changed temperature. To prevent continuous power consumption for maintaining system behavior, a locking system can be added which does not require any power during operation. A new...

Ortho-Planar Springs: Design of a zero stiffness mechanism for energy harvesting applications

Vibrational energy harvesters convert ambient kinetic energy into electrical energy that can be used to power electronic devices. Harvesting in the low frequency range over a wide bandwidth proves to be a challenging task. In this paper it is argued that stiffness cancellation can be used to effectively operate in this range. A conceptual design...

Vibration energy harvesting: Optimal non-linear motion

An increased amount of work is done towards opti- mizing the mechanical design of vibrational energy harvesters in order to cope with varying ambient conditions. Here the performance of a piezoelectric energy harvester with varying non-linear spring characteristics is modelled and experimentally veri- fied, determining the optimal non-linear...

Modelling and validation of impact response in compliant nechanisms: Using pseudo-rigid-body modelling and rigid body dynamics

Modelling of the behaviour of compliant mechanisms leads to a better understanding and synthesis of designed mechanisms. Static and dynamic responses for compliant mechanisms have been researched extensively. While impact modelling is a well known field in rigid body dynamics, impact modelling in compliant mechanisms research is lacking. By...

A Fully Compliant Force Balanced Oscillator

The Design of a 2-DOF Inertial Motion Harvester for a Mechanical Watch

Energy harvesters extract energy from the ambient environment and can be used to power electronic devices. One interesting application of these harvesters is the medical field where in the future they might be used to power pacemakers or medicine pumps. One common energy harvester is the automatic wrist watch, a 1 degree of freedom (DOF)...

Design of a Compliant Escapement Mechanism

This thesis describes the design process for an iso-frequent oscillator. Instead of designing the perfect linear spring for a harmonic oscillator, non-linearities in the force deflection behavior of the spring are allowed. These inperfections are then compensated by propper transmission design.

Design of a passive self-levelling device

In this paper the design of a passive self-levelling device is presented. Self-levelling means that the device adjusts itself to compensate for inclinations of the floor without user intervention. This has the advantage that a single device can be used on floors with various inclinations without losing its functionality. First an analysis is...

Design for specified stiffness in precision engineering

Precision engineering impacts every one, every day, by enabling the fabrication techniques and functions required for 21st technological revolutions. Various applications, from display technologies to sensor systems to optical networks make use of so called microelectromechanical systems (MEMS). Motions at micro level with monolithic structures...

Design of a zero stiffness six degrees of freedom compliant precision stage

This paper presents the first zero stiffness six degrees of freedom (DoF) compliant precision stage. To deal with problems like backlash, friction and lubrication for performing ultra-precise positioning in a vacuum environment, a novel compliant structure is proposed. All six degrees of freedom are statically balanced (i.e. near zero stiffness)...