Semester project proposals – Spring 2020

Integrated actuators – Prof. Y. Perriard

Note: Projects are intended for Microengineering, Electrical Engineering, Computer Science and Mechanical Engineering sections.

For information and registrations contact:

Transportation fees will be reimbursed.

1. Alternative, Magnetically-Levitated Motor Topologies for High Speed
Patricio Peralta

At LAI, a micro motor with a magnetic bearing is being developed in collaboration with a Swiss company. The magnetically levitated drive is designed to reach speeds of 100 krpm. To reach this objective, different motor types can be constructed. These can be rated by different criteria, such as motor loss minimization, simplicity of fabrication, bearing stability, etc.
Among this motor portfolio, only one motor topology has been constructed until now. Nevertheless, other motor types are still adequate. Their optimization, and ultimately, their construction, would enable to perform a head-to-head comparison of the advantages and disadvantages of different motor types of high scientific interests.
The work will initially demand an overview of levitation system topologies and their geometries. Once this is chosen, analytical and computational models are to be constructed and analyzed striving towards high-speed operation and stiff levitation.
The micro motor has to ultimately be constructed. The construction of the motor envisions state of the art magnetic materials, and high precision manufacturing involving 3D printers and laser cutting technology.

2. Development of a Framework for Topology Optimization of Compliant Mechanisms
Adrien Thabuis, Sean Thomas

Topology Optimization investigates the distribution of material inside a discretized design domain to improve an objective. It has become an innovating and revolutionary way to create complex and organic designs. In this new age of additive manufacturing such as 3D printing, the capacity to fabricate such new designs have become a reality. Compliant mechanisms, on the other hand, are a well-established solution to create miniaturized systems. By combining these mechanisms with topology optimization, we can create unique solutions that can further innovate this space.
The goal of this project is to extend an existing topology optimization framework in Python to design compliant mechanisms. The current version maximizes the rigidity of 3D mechanical structures subject to various loads. It should be modified to maximize the strain inside the structure in order to result in compliant mechanisms. A Matlab framework for 2D has already been developed to this purpose and can be used as a reference. A prototype inspired by this algorithmic design can then be fabricated and tested.
The student will have the opportunity to explore the inner workings of the topology optimization algorithm so as to adapt it. They will also be able to design and fabricate a novel system that has been imagined completely by a computer algorithm. 

Source :

Evolution of the topology for an optimized compliant force inverter.

3. Drone-ready Robotic Gripper powered by Shape Memory Alloys
Sean Thomas

The goal of this project is to create a functional prototype of a compact lightweight gripper that harnesses the power of Shape Memory Alloys (SMA). The use of compliant mechanisms and flexible joints to create a miniaturized gripper has now become a reliable solution. The objective would be to explore various compliant solutions, fabricate them and render them compatible with the exotic behaviour of SMAs.
The student will be asked to exercise his creative muscles by designing an innovative gripper using novel systems focused on compliant mechanisms. The student will also have the opportunity to experience the Shape Memory Effect to find novel ways to couple this behaviour with the compliant system.
The hope of this project is create a low-weight high-force output gripper solution that can be used in numerous applications such as drones and surgical tools.

Source :

4. Design, miniaturization and manufacture of coupled inductors for ultra-high voltage power supplies
Raphaël Mottet, Thomas Martinez

The Center for Artificial Muscles (CAM) is currently designing a new type of vascular assist device based on the Dielectric Elastomer Actuator (DEA) technology. To actuate such a device, it is necessary to generate extremely high voltages ranging between 5 to 10 kV from a low voltage power supply such as a 12 V battery. Because of the final location of the electronics inside the body, it must be designed as small as possible while keeping in mind the requirements imposed by the voltage levels that are manipulated. The topology used to supply the required voltages is the DC-DC Flyback, which has as its center piece the most critical component to design and manufacture: the coupled inductor.
The goal of this project is thus to explore and implement numerous solutions which could help further reduce the size of currently manufactured inductors while working with tight specification requirements. All of the created coupled inductors will be directly tested in situ and the most promising design may be sent for produced by a subcontractor.

5. High-voltage power supply for tethered drones
Raphaël Mottet, Camilo Hernandez

The applications for flying drones have been increasing in recent years and every day new applications are being developed. Nevertheless, flying time (the autonomy) of the drone is generally limited by the advances in battery technology. 

Knowing that some applications require longer fly time, even unlimited flight time in some cases (i.e. early fire and avalanche detection), the laboratory of integrated actuators (LAI) at EPFL is investigating the development of tethered power supply methods for unmanned aerial systems. 

In this particular project, we are looking to reduce the weight of both the tether (cable) and the voltage converter on board of the drone to be able to reduce the amount of power required to keep the drone in the air. AC and DC will be studied to determine the most efficient mode for power transmission in short distances (100 m to 200 m) and several power transformation methods will be studied. At the end of the project the developed prototype for a high voltage (HV) tether system will be tested using a racing drone and the efficiency will be validated.