Integrated actuators – Prof. Y. Perriard
Note: Projects are intended for Microengineering, Electrical Engineering, Computer Science and Mechanical Engineering sections.
For information and registrations contact:
- Prof. Yves Perriard at: [email protected]
- Paolo Germano at: [email protected]
Transportation fees between EPFL and Neuchâtel will be covered.
- Project # 1 – Acoustic for wireless power transmission
- Maribel Caceres Rivera
Acoustic wireless power transmission is an exciting emerging technology that provides a strong alternative to traditional inductive coupling, especially when it comes to power delivery efficiency. In this method, a piezoelectric harvester acts as the receiver, converting acoustic energy into electrical energy. This approach makes it possible to design smaller, more compact implantable devices than those powered by inductive coupling, and it can also reach greater depths inside the body.
Project Tasks:
Review the state of the acoustic devices for implantable medical devices.
Define the detailed system architecture, considering commercially available components to transmit power wirelessly.
Account for size limitations specific to implantable devices.
Design a complete schematic using Altium Designer or KiCad for the proposed topology.
Validate in a final setup the power transmission.
Skills:
COMSOL, PCB design (Altium, Kicad, OrCAD…)
Simulation tools (LTSPICE, PSPICE or SPICE KEYSIGHT )
References
[1] Liu, X., Wang, Y., Wang, G., Ma, Y., Zheng, Z., Fan, K., Liu, J., Zhou, B., Wang, G., You, Z., Fang, Y., Wang, X., & Niu, S. (2022). An ultrasound-driven implantable wireless energy harvesting system using a triboelectric transducer. Matter, 5(12), 4315–4331.
[2] Kim A, Powell CR, Ziaie B. An implantable pressure sensing system with electromechanical interrogation scheme. IEEE Trans Biomed Eng. 2014 Jul;61(7):2209-17. doi: 10.1109/TBME.2014.2318023. PMID: 24800754.
. - Project # 2 – Flyback converter for high voltage applications
- Maribel Caceres Rivera
The flyback converter is a DC-DC topology capable of stepping up voltages, ranging from a few volts to kilovolt levels. This topology is commonly used in automobiles, instrumentation devices, and, in our case, for powering Dielectric Elastomer Actuators (DEAs) in artificial muscles. It offers several advantages compared to other voltage step-up topologies, such as a reduced number of components and a high voltage conversion ratio.
Nevertheless, this topology also presents challenges. The transformer must be carefully designed, primarily due to parasitic effects. In addition, the high voltages required for the MOSFETs pose significant design considerations. Flyback converters can also be implemented bidirectionally, which enables energy recovery from the load (Dielectric Elastomer Actuator).
With this project, the student will gain analytical, simulation, and experimental validation experience by developing a flyback converter to power DEAs.
Project Tasks:
– Gain familiarity with the topology and its operation in different modes according to the load.
– Develop a mathematical analysis to determine the operating conditions.
– Select and simulate the topology with appropriate components to minimize parasitic effects.
– Implement the topology to achieve high voltages on the order of kilovolts.
– Validate the final architecture by comparing the mathematical analysis and simulation results.
Skills:
PCB design (Altium, Kicad, OrCAD…)
Simulation tools (LTSPICE, PSPICE or SPICE KEYSIGHT )
References
[1] P. Thummala, Z. Zhang and M. A. E. Andersen, “High voltage Bi-directional flyback converter for capacitive actuator,” 2013 15th European Conference on Power Electronics and Applications (EPE), Lille, France, 2013, pp. 1-10, doi: 10.1109/EPE.2013.6634458.
[2] V. Ravi, C. Kuldip and N. Lakshminarasamma, “High Voltage Flyback Converter for Pulsed Loaded Applications,” 2020 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES), Jaipur, India, 2020, pp. 1-6, doi: 10.1109/PEDES49360.2020.9379557.
. - Project # 3 – Improvement of Implantable Cardiac Assist models through SPICE and Multiphysics simulations
- Marc-Olivier Arrigo, Alexis Boegli
In the scope of the Center for Artificial Muscles’ (CAM) current DEA-centric projects, great challenges are posed by the high voltage requirements of Dielectric Elastomer Actuators stimulation. While generating high voltages is trivial, applying those voltages in a way that does not deteriorate the actuators necessitates to take the underlying physics into consideration. As such, development of driving electronics would benefit a lot from relevant and valid (SPICE Simulation Program with Integrated Circuit Emphasis) and other platform’s simulation models for such unusual components.
As a student, you will be responsible for:
– Perform an overview of all applicable simulation technologies, whether it is SPICE-derived or Multiphysics, and analyze the needs and shortcomings of every of those.
– Investigate the main basic models used to characterize DEAs manufactured in the lab
– Explore more complex SPICE models, such as distributed constants, and justify their topologies by relating to the manufacturing process.
– Research the impact of actuation on the models and investigate how the constants evolve when mechanical actuation occurs.
– Explore more complex solutions, such as analog hardware description or Multiphysics simulation to refine the models.
– Validate the relevance of each step using real data and performing impedance measurements on DEAs.
The student will gain knowledge in electrical and Multiphysics simulation, as well as explore the world of non-ideal electronics while performing research on a field unusual to electrical and electronics engineering. A good understanding of basic electrical engineering along with an interest in circuit simulation is required.
Figure 1: Dielectric Elastomer Actuator
Figure 2: DEA In-Situ (animal trial)
[1] R van Kessel et al 2021 Smart Mater. Struct. 30 035021
. - Project # 4 – Development, programming and test of a modular 2.4 GHz LoRa RF link
- Marc-Olivier Arrigo, Alexis Boegli, Maribel Caceres Rivera
In the scope of the Center for Artificial Muscles’ (CAM) Cardiac Assist Project, there is a need for data such as real-time current and voltage applied to the actuator to be transmitted wirelessly to the exterior. An external terminal should be able to monitor such signals to guarantee proper operation of the actuator. 2.4 GHz LoRa has been selected as a valid communication protocol to access an implanted cardiac module remotely. The lab needs a modular circuit that could integrate in the pre-selected architecture of the driving electronics, revolving around a STM32U3 ARM 32-bit microcontroller.
As a student, you will be responsible for:
– Integrate a valid communication topology in the existing electronic ecosystem of the lab, as well as a second endpoint for testing purposes, for instance, LoRa transceiver modules, that would allow for bidirectional communication.
– Select and/or design an antenna that would suit the application and be adapted to the media (muscle, fat, etc.)
– Write the firmware that supports the communication link in the existing software ecosystem or real-time OS.
– Test and characterize (losses, reliability, range) the link and validate the circuit in a mock-up of the target environment.
The student will gain knowledge in embedded software programming for wireless communication and RF link characterization. A good understanding of basic electrical engineering and prior experience with RF modules integration, with an interest in wireless technologies is required.
[1] Aliqab K, Nadeem I, Khan SR. A Comprehensive Review of In-Body Biomedical Antennas: Design, Challenges and Applications. Micromachines (Basel). 2023 Jul 21;14(7):1472. doi: 10.3390/mi14071472. PMID: 37512782; PMCID: PMC10385670.
. - Project # 5 – Self-sensing for artificial muscles in facial reanimation
- Xiaohan Han, Markus Koenigsdorff
Project background:
Dielectric elastomer actuators (DEAs) are a class of soft actuators composed of an electrically insulating polymer layer sandwiched between two flexible electrodes. It has been widely researched as promising candidates for artificial muscles in implantable biomedical devices and bioinspired robotics. Additionally, DEAs can be modelled as compliant capacitors: their capacitance changes with deformation, allowing the actuator itself to act as a self-sensing element. In systems with multiple DEAs connected in parallel, differences in capacitance can be exploited to increase sensitivity and monitor the actuators’ state in real time.
Objectives:
– Investigate the self-sensing capabilities of DEAs for real-time monitoring of actuator deformation.
– Explore parallel DEA configurations to enhance sensing sensitivity.
– Fabricate and characterize prototype DEAs to correlate electrical measurements with mechanical deformation.
Desired Skills:
– Positive attitude with prototyping and fabrication of soft materials.
– Basic understanding of electronics and sensor measurement techniques.
– Data analysis skills (Python, MATLAB, or similar tools).
– Ability to communicate technical results clearly.
. - Project # 6 – Kresling Origami as Biasing Mechanism for Dielectric Elastomer Actuators
- Xiaohan Han, Markus Koenigsdorff
Project background:
Dielectric elastomer actuators (DEAs) are high-performance soft actuators, but the generated strain depends heavily on the biasing system. Traditional biasing approaches include masses, springs, and negative bias springs. Kresling origami is a twisted folding pattern with unique bistable properties. This project investigates whether Kresling origami can provide optimal pre-stretch for stack DEAs to achieve high strains.
Figure 1 Kresling pattern, Park et al. (2019), Proc. SPIE 10966, DOI: 10.1117/12.2514374
Objectives:
– Fabricate Kresling structures using appropriate materials and integrate them with DEA prototypes.
– Characterize the achievable strain and actuation performance.
Desired skills:
– Hands-on fabrication skills for creating origami structures and soft actuator prototypes.
– Experience with CAD software.
– Proficiency in experimental design, data collection, and analysis.
– Strong presentation and communication skills.
. - Project # 7 – Development of an I2C extension board for a motor controller PCB
- Maël Dagon, Andres Osorio Salazar
Context
Diabetic patients often suffer from peripheral neuropathy, which causes foot insensitivity leading to high plantar pressure points (HPP). HPP can lead to ulcers and potentially amputations. To redistribute plantar pressure, we developed a reconfigurable insole containing an array of reconfigurable modules.
Objective
Each module is driven by a small DC motor and can be moved up or down with a range of ~5mm. A PCB containing electronics to drive 18 modules simultaneously has been developed (Figure 1). The position of the motors is measured without sensors using a ripple counting approach. The goal of this project is to develop an extension board to extend the number of motors being controlled by the board. Then, the I2C communication between the main PCB and extension board must be implemented using existing code as well as updating some functions.
Content of the project:
– Extension PCB development: Develop and manufacture an I2C extension board for the current main PCB.
– I2C communication: Manage seamless communication between the main PCB and the extension board.
– System validation: Test and validate the developed hardware and software.
Profile
Type of work: 10% theory / 40% hardware / 30% software / 20% experiments
– Good knowledge in programming, ideally experience with STM32 architecture
– Knowledge in control electronics and motor physics
– Knowledge in PCB design, using KiCAD or similar software
– Ability to work autonomously
– Ability to setup and conduct relevant experimental tests
Figure 1 Motor-driving PCB.
. - Project # 8 – Topology optimization in frequency domain
- Marc Favier
Topology Optimization (TO) aims at generating new geometries to gain in performances. The goal of this project is to work with oscillating systems (piezoelectric ultrasonic actuators), define required parameters for a TO and increases some measure of performances such as mass reduction, maximum force output. Well mastered on static problems, TO is challenging for frequency domain analysis, and time dependant analysis. The student is expected to pick a FEM software and implement the problem in a way compatible with frequency domain and TO. If the project goes well, non-linear dynamics (contact and friction force) can be added to design a multi-body TO.
Approach:
1. Software and methodology choice
– Choice between Comsol, Python, Matlab
– Methodology definition
– Problems specific to frequency domain analysis
2. Simulation setup:
– Design space definition
– Objective function definition
3. Performance evaluation:
– Innovative geometries generation
– Objective improvement
Preferred Qualifications:
– Experience with FEA either in Python, Matlab or Comsol
– Proficiency in mathematics, especially optimization
– Understanding of Topology Optimization
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