Student Projects

Our research activities focus on the study and development of NEMS/MEMS resonators. We target two main applications: sensors and communications. We follow a holistic approach so we have projects/ideas on analysis, modelling, fabrication, characterization, integration, and application of these devices.
Below you can find a list with some ideas for semester and master projects. Do not hesitate to contact us because we will likely be able to find a project that matches your motivations. 
Pour les étudiants francophones, s’il vous plaît ne pas hésiter à nous  contacter, car nous pouvons également parler en français.


Collaborations with companies

 Piezoelectric MEMS for vibrations sensing

Master Project

You will mostly do Design and Fabrication

We want to miniaturize current SoA vibration sensors

The project

Vibration sensors (aka vibrometers) are essential components to keep safety and reliability of different types of machines, e.g. plane engines. A vibrometer is able to detect very small vibrations, that coming from either acceleration caused at the clamp or by pressure variations in the environment. In the frame of aerospace industry, the extremely strict requirements for safety, resolution, endurance and lifetime have caused the technology to evolve very slowly. The idea of the project is to analyze if a MEMS based device would be of interest as the next generation vibrometers. Analysis of the different transduction possibilities, design and fabrication in the CMi clean room at EPFL will be performed.

The Company

Meggitt Sensing Systems Switzerland (MSS Switzerland) leads the market in sensing and monitoring solutions, specialising in smart engineering for extreme environments. Our 60+ years of sensor and system expertise means our solutions are trusted by original equipment manufacturers around the world. MSS Switzerland was founded as Vibro-Meter® back in 1952. This became a Meggitt company in 1998 and in 2006 was integrated in the Meggitt Sensing Systems division.

Fig. 1 Schematic drawing of one concept of piezo vibrometer. A membrane with piezoelectric material will generate charges upon vertical movement that will be collected by the electrodes. A suspended mass will amplify the effect of external vibrations. Fig. 2 Schematic drawing of another concept of piezo vibrometer. In this case, a metallic membrane will deflect upon external vibrations or changes in pressure. This movement will modify the resonance frequency of the piezoelectric acoustic resonator placed underneath.
Project Components:

The project will be carried at the Advanced NEMS group at EPFL (Lausanne), but with often visits to the Meggit-sensing site in Fribourg. The main tasks involved in the project will be:

  • Study of specifications/requirements from aerospace applications (10% of the time – 1-2 weeks)
  • Study of the State of the Art of vibrometers and microphones (20% of the time – 3 weeks)
  • Design of novel vibrometer (30% of the time – 4-5 weeks)
  • Fabrication first prototypes (40% of the time – 5 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges
  • Knowledge of a simulation (FEM) software is a plus
  • Knowledge in cleanroom processes is a plus

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva

Micro-optomechanical systems before integration

Semester/Master Project

You will do Design and Fabrication

We want to make the optical sensor of the Industry 4.0

The project

The availability of suitable sensors becomes increasingly challenging in harsh environments , typical of many industrial settings, where e.g. high temperatures, high pressures, large electromagnetic fields or radiation hinder the use of conventional electronic transducers. Optical-based sensors provide a route towards circumventing these difficulties. In particular, micro-optomechanical systems (MOMS) combining a mechanical element with optical readout techniques can be fabricated to tolerate harsh conditions. The ability to build them into optical fibers provides ease of scalability, distribution and installation in systems requiring multiple sensors, and their integration into available optical communication networks. The project aims at designing and fabricating micro-mechanical devices and resonators to be assembled in the final product with optical readout. There will be the opportunity to participate in the overall prototypes and products development, interact with external suppliers and clients (in defense, energy, automotive, aerospace), learn new challenging techniques and discover the tech startups world. The master project will be sponsored. Possibility to join the startup after the project.

The company

The Miraex is a young startup based at the EPFL Innovation Park. Miraex unique combination of nanotechnoly, new materials, photonics and artificial intelligence provides the missing tool for predictive maintenance in harsh environments. By harnessing the power of light, Miraex products enable smarter and greener factories for the Industry 4.0 Possibility to join the startup after the project.

MEMS Wafer characterization

Fig. 1 Micro-optomechanical systems (MOMS) before integration in the prototype

Project Components:

The project will be carried out between Miraex (EPFL Innovation Park) and the Advanced NEMS group at EPFL (Lausanne). The main tasks involved in the project will be:

  • Optimize design and fabrication process flow (20% of the time – 3 weeks)
  • Fabrication of the new generation of sensors in CMi (60% of the time – 8-10 weeks)
  • Integration in the final product (20% of the time – 3 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges
  • Knowledge in cleanroom processes is a plus

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva


Resonators with Microchannels

 PMUTs for acoustic spectroscopy

Master Project

You will mostly do Design and Fabrication

We want to analyze biosamples via acoustic waves

The project

Piezoelectric micromachined ultrasound transducers (PMUTs) are suspended composite membranes capable of both sensing and sending sound waves that can interact with the environment of interest. They are used in wide variety of everyday applications, from radar/sonar to non-destructive material testing and medical imaging. One emerging area of interest is in measuring acoustic spectroscopy. We want to do that in microfluidic channels by placing PMUTs above and below the channels. In this way, there is no influence on the sample as it flows along the channels and measurements are incredibly sensitive. In this project, the student will design and fabricate PMUTs with integrated microchannels.

Fig. 1 Schematic and working principle of PMUTs. Image taken from Qiu et al. Fig. 2 SEM images of AlN PMUT from Lu et al.
Project Components:

The main tasks involved in the project will be:

  • Literature review of PMUTs and microfluidics (30% of the time – 3 weeks)
  • Design and Fabrication of the resonators in CMi (50% of the time – 7-8 weeks)
  • Microfluidic integration (20% of the time – 3 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges
  • Knowledge of cleanroom processes would be welcome

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva

Kaitlin Howell

 Proposition of process flow for the fabrication of the new generation

Semester Project

You will mostly do Design and Fabrication

We want to optimize the fabrication of a new generation of suspended microchannel resonators

The project

Suspended microchannel resonators (SMRs) consist of microfluidic channels embedded in vibrating structures. Their configuration allows for the study of diverse liquids, including biological fluids. As such, we intend to use those devices for the detection of cancer cells. The first generation of such devices has already been fabricated, characterized and used for preliminary experiments. The objective of this project is to optimize the fabrication process of the second generation of devices. We want to investigate the feasibility of a simpler (and thus shorter and cheaper) fabrication process for the embedded microchannels.

Fig. 1: SEM picture of the cross-section of the first generation of (rectangular) microchannels. Image provided by Annalisa De Pastina. Fig. 2: Proposition of process flow for the fabrication of the new generation of (circular) microchannels.
Project Components:

The main tasks involved in the project will be:

  • Drawing of lithography masks for the design of the microchannels
  • Fabrication of the microchannels in CMi
  • Characterization of the fabrication at the SEM
Desired Skills:
  • Autonomy
  • Cleanroom experience would be welcome

Type of Project:

Section(s):

Contact(s):

Semester Project

Microengineering; Mechanical Engineering

Guillermo Villanueva

Damien Maillard


Acoustic mode resonators

 FEM model of LAMB resonator

Semester Project

You will mostly do Simulations

We want to find the optimal parameters to make the best LAMB wave resonators

The project

LAMB wave resonators have the potential to be used as passive RFID tags for identification and tracking of small biological molecules. Electromechanical coupling (kt^2) and quality factor (Q) are the two most important factors for improving the performance of the resonator. The idea behind the project is to improve kt^2 and Q by optimizing different geometrical parameters through COMSOL simulations. FEM model (Fig. 1) has already been designed and optimize to match the state-of-the-art but it requires further optimization for highly miniaturize resonators (6×4 μm). Student’s job will be to sweep important geometrical parameters (Fig. 2) such as anchor length (La), anchor width (Wa), bus with (Wb), finger gap (Wg) and electrode coverage to study their impact on the performance of the resonator.

Fig. 1: FEM model of LAMB resonator. Fig. 2: Design geometry showing important parameters. [Ref] G.Piazza et al, Journal of Microelectromechanical systems, 2018
Project Components:

The main tasks involved in the project will be:

  • Literature review of LAMB wave resonators including S0 and SH0 modes (10% of the time – 1-2 weeks)
  • Introduction to COMSOL and already simulated model (10% of the time – 1-2 weeks)
  • Optimization of COMSOL model (80% of the time – 10-12 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Interest in COMSOL simulations
  • Knowledge in MEMS is desirable

Type of Project:

Section(s):

Contact(s):

Semester Project

Microengineering; Mechanical Engineering

Guillermo Villanueva

Muhammad Faizan

 SEM image of a µTag internalized by the cell.       [Ref] H. Wong et al, PhysRev Applied, 2017

Master Project

You will do mostly Design and Fabrication

We want to probe cell properties from the inside

Master project

Recently, a number of cell probing techniques have been developed to study the behaviour and properties of a single cell. Most of them are invasive or require optical detection. The goal of the project is to develop a wireless cell-probing system similar to an RFID system that will identify and track the movement of an individual cell in real time. Fig. 1 shows the insertion of such small device in a mouse macrophage (white blood cell). The idea is to use a piezoelectrically actuated acoustic resonator as an RFID tag that should be small enough to easily internalized and be efficient enough to send back the data from inside the cell. However, little work has been conducted to realize the full potential of acoustic devices with critical dimensions less than a few microns. The main goal of the student will be to fabricate LAMB wave resonators on thin film lithium niobate (Fig. 2). The student will get hands on experience with different microfabrication tools related to e-beam lithography, wet/dry etching and metrology.

 Fig 1: SEM image of a µTag internalized by the cell.    [Ref] H. Wong et al, PhysRev Applied, 2017 Fig 2: SEM image of a fabricated miniaturize acoustic resonator.
Fig 1: SEM image of a µTag internalized by the cell [Ref] H. Wong et al, PhysRev Applied, 2017. Fig. 2: SEM image of a fabricated miniaturized acoustic resonator.
Project Components:

The main tasks involved in the project will be:

  • Literature review of LAMB wave resonators including S0 and SH0 modes (10% of the time – 1-2 weeks)
  • Related cleanroom trainings at CMi (10% of the time – 1-2 weeks)
  • Design and fabrication (60% of the time – 8-9 weeks)
  • Characterization of fabricated devices (20% of the time – 2-3 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Interested in microfabrication
  • Knowledge of MEMS is desirable

Type of Project:

Section(s):

Contact(s):

Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva

Muhammad Faizan

SAW-based acoustic spectrometer

Master Project

You will mostly do Simulation and Fabrication

We want to analyze bio samples via acoustic waves

The project

Acoustic spectroscopy is being increasingly used to characterized different bio-materials and for the detection of biomolecules. The idea is to design and fabricate a miniaturized platform for the detection and characterization of cancerous cells by using Surface Acoustic Waves (SAW). The proposed platform consists of a pair of Interdigital electrodes (IDTs) for the generation and reception of SAW waves with an embedded microchannel in between for the trapping of cells or other biological entitiesas shown in Fig. 1. Information such as the elasticity of the sample, can be determined by measuring the phase change of the resultant SAW waves after passing through the sample.

Fig 1: (a) 3D simulation model. (b) Cross-sectional image from the central axis of a microcavity. Ref.: R. J. Cote and O. Tigli, Lab on a Chip interrogation of single tumour cells in Lab Chip, vol. 16, pp. 163-171, 2016.
Project Components:

The main tasks involved in the project will be:

  • Literature review of SAW-based acoustic spectroscopy (25% of the time – 3-4 weeks)
  • Design and FEM modelling of the proposed platform (25% of the time – 3-4 weeks)
  • Fabrication of the resonators in CMi (40% of the time – 5-6 weeks)
  • Preliminary characterization of the resonators (10% of the time – 1-2 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges
  • Knowledge in cleanroom processes is a plus

Type of Project:

Section(s):

Contact(s):

Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva

Muhammad Faizan


Thin Film Optimization

 SEM image of released cantilever array

Semester/Master Project

You will do Fabrication and Characterization

We want sensors with a high k-material to investigate actuation at the nanoscale

The project

There is immense interest in fabricating nanoelectromechanical systems for creating extremely sensitive sensors or highly efficient actuators for measurement of temperature, mass, radiation, etc. or creation of nanoelectromechanical relays. Current systems are largely based on piezoelectric or capacitive mechanisms, but there is an emerging field in utilizing second order or dielectric mechanisms to reduce fabrication cost and difficulty while maintaining high sensitivity/actuation. However, producing sensors from dielectric materials have many unanswered questions and often large discrepancies between theory and experiment. In this project, the student will study the theory behind NEMS and different electromechanical transduction methods, then can help design, simulate, fabricate or conduct experiments of sensors with a high k-material to investigate actuation at the nanoscale.

Close-up SEM image of a released cantilever with 100-nm thickness, comprised of molybdenum and hafnium oxide. Alignment of laser on released cantilever for optical measurements of resonance frequency and deflection.
Fig 1 Close-up SEM image of a released cantilever with 100-nm thickness, comprised of molybdenum and hafnium oxide. Fig. 2 Alignment of laser on released cantilever for optical measurements of resonance frequency and deflection.
Semester Project Components:

The main tasks involved in the project will be:

  • Understand theory of NEMS, electromechanical transduction
  • Introduction to electrical and optical measurements of resonators
  • Measurements of beams fabricated in CMi
Master Project Components:

The main tasks involved in the project will be:

  • Understand theory of NEMS, electromechanical transduction
  • Introduction to CMi and prepare design/process flow
  • Fabrication of dielectric beams
  • Electrical and optical measurements of resonators
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering

Guillermo Villanueva

Kaitlin Howell

 cross-sectional SEM image of PLD-grown PZT

Semester/Master Project

You will do Theoretical study and Fabrication

We want to obtain the best PZT layers

The project

Piezoelectric materials, such as lead zirconate titanate (PZT) and aluminum nitride (AlN), are the mainstay materials in MEMS for efficient actuation and sensing applications. When moving from the established MEMS fabrication to NEMS, consistent deposition of highly piezoelectric, nanometer-thick films becomes increasingly important. Several different deposition methods are possible for PZT, including sol-gel processing, sputter deposition and pulsed laser deposition (PLD). Of the three, PLD offers the opportunity to deposit epitaxial, stoichiometric PZT at high temperature. PLD is a physical vapor deposition, using a pulsed laser to vaporize the material of interest off a target onto a substrate in an ultra-high vacuum chamber. Depositing high-quality PZT thin films requires heavy optimization of the deposition parameters, high purity targets and proper substrates for epitaxial growth. In this project, the student will study PLD, piezoelectricity and PZT and contribute to the deposition and fabrication of PZT in CMi.

 Example of PLD system capable of depositing PZT  cross-sectional SEM image of PLD-grown PZT
Fig 1 Example of PLD system capable of depositing PZT Reference: D. H. A. Blank, M. Dekkers, and G. Rijnders, “Pulsed laser deposition in Twente: from research tool towards industrial deposition,” J. Phys. D. Appl. Phys., vol. 47, no. 3, p. 34006, 2014. Fig. 2 Above, cross-sectional SEM image of PLD-grown PZT on an SRO/YSZ electrode. Below, SEM image of released PZT-based cantilever. Reference: M. D. Nguyen et al., “Characterization of epitaxial Pb(Zr,Ti)O 3 thin films deposited by pulsed laser deposition on silicon cantilevers,” J. Micromechanics Microengineering, vol. 20, no. 8, p. 85022, 2010.
Semester Project Components:

The main tasks involved in the project will be:

  • Theoretical study of piezoelectricity, PZT, PLD
  • Introduction to CMi and installed PLD machine
  • Optimizing PZT deposition and dry etching in cleanroom
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoys learning and facing new challenges
  • Knowledge in cleanroom processes is a plus

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering

Guillermo Villanueva

Kaitlin Howell


Complex Dynamics

PCB and circuit design for NEMS characterization

Semester/Master Project

You will mostly do Circuit Design

We want to find the best platform to characterize NEMS

The project

NEMS have a large potential for sensing applications due to their size. However, at the same time, NEMS are difficult to integrate with electronics due to huge impedance mismatching and poor amplification. In this project, a circuit will be designed with background cancellation capabilities and/or impedance matching. Then, in collaboration with the Electronics Workshop, a PCB will be modelled, designed and fabricated that can be used to make measurements of a NEMS device. For the modelling, an equivalent circuit will be created to analyze the impedance matching network and amplification stage for the best integration with NEMS.

 Schematic of two measurement circuits PCB with Camipro for scale
Fig. 1 Equivalent Circuits with NEMS Resonator and (top) a balancing bridge and (bottom) a LC-tank. Fig. 2 PCB with NEMS device in center. Camipro card for scale.
Project Components:

The main tasks involved in the project will be:

  • Literature review of existing methods (20% of the time – 3 weeks)
  • Design of circuit, including resonator model (40% of the time – 6 weeks)
  • Fabrication of the PCB (20% of the time – 3 weeks)
  • NEMS characterization (20% of the time – 3 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoy learning and facing new challenges
  • Knowledge of analog circuit design is a plus (even a must)

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Electrical Engineering, Microengineering; Mechanical Engineering

Guillermo Villanueva

 Piezoelectric

Semester/Master Project

You will do Simulations, Fabrication and Characterization

We want to understand the most complex devices.

The project

Coupling phenomena can be found in most of physical systems in nature. Coupling increases the systems’ dimensionality (making the systems more complex) and, in some cases, also the functionality (making the “whole greater than the sum of its parts”). In Nano-electromechanical Systems (NEMS), coupling between neighboring devices can be achieved, for example, via mechanics. A common ledge (support) for different devices will effectively couple them, and therefore collective dynamics might emerge. It is necessary, however, that this coupling is strong enough so that the devices actually “coupled”. It is the purpose of this project to analyze how the strength of this linear coupling depends on the physical constraints that act on adjacent devices. This will be studied using directly as well as parametrically driven responses.

Fig. 1: Coupled piezoelectric NEMS using the overhanging ledge in one of the anchoring points. Individual dimensions are 9µm*450nm*210nm.
Project Components:

The main tasks involved in the project will be:

  • Simulation and analytical calculation of coupling coefficients (30% of the time – 4-5 weeks)
  • Design and fabrication of a battery of devices (50% of the time – 7-8 weeks)
  • Characterization of the frequencies, quality factors and coupling rates (20% of the time – 3 weeks)
Desired Skills:
  • Fluency in English
  • Autonomy
  • Enjoy learning and facing new challenges
  • Knowledge of Finite Element Modelling is a plus

Type of Project:

Section(s):

Contact(s):

Semester/Master Project

Microengineering; Mechanical Engineering; Electrical Engineering

Guillermo Villanueva