2 PhD Positions: Designing intelligence in battery-less micromechanical structures

Intelligent devices are everywhere (in sensors monitoring infrastructure, in medical prostheses, wearables and smart speakers). However, their autonomy is severely constrained by the need for large batteries, which also have a negative environmental impact. A recent study forecasted that, by 2025, we will be throwing away 80 million batteries a day. We are looking for two Ph.D. students to overcome this challenge using intelligent micromechanical systems.

In the same way that automatic Swiss watches power themselves from the motion of the wearer, we will design and make (micro)-mechanical computing elements that use energy from ambient vibrations – without the need for power wires or batteries. These elements will rely on geometric nonlinearities to perform complex tasks. In fact, while nonlinearity is usually avoided in mechanical designs, here we will leverage it to achieve unprecedented computational capabilities:  by combining nonlinear elements as ‘lego pieces’ a targeted response will be achieved. 

Complex computations will require divisions into subtasks. Therefore, two distinct yet interconnected projects are proposed:

Project 1: Mechanical harvesting of ambient vibrations. The student will design micro-mechanical systems that can harvest stochastic (random) ambient vibrations and convert the resulting energy in the oscillation of a resonator or in the deformation of an elastic structure.

Project 2: Reprogrammable micromechanical computers. The student will design micro-mechanical structures capable of processing information by using nonlinear phenomena such as buckling and instabilities.

The outcome of the two projects leads building blocks that, when combined, can perform logical operations solely relying on mechanical energy.

For both projects the work will be mostly theoretical and numerical. State-of-the art modeling and reduction techniques will serve the design process.  The concepts will be validated in laser-cut or 3D printed prototypes. The resulting designs will be micro-fabricated in a cleanroom by an additional team member later. The project is a collaboration between ETH Zürich and the AMOLF Institute in Amsterdam, the Netherlands (Dr. Marc Serra Garcia). Students will be based at ETH, and will make several visits to AMOLF to conduct experiments.

The tasks of the student will be:

• Design mechanical structures that use nonlinear elasticity to perform computations using ambient energy
• Develop efficient simulation algorithms capable of tackling complex devices consisting of thousands of parts
• Conducting table-top experiments to validate the concepts

The envisioned starting date is October/November 2024.

We are looking for two students with experience (or strong interest to learn) in the topics of:

• Finite Element Method (FEM) simulation, specifically nonlinear FEM
• Model reduction and substructuring component mode synthesis methods
• Nonlinear and stochastic dynamics
• Microelectromechanical systems (MEMS)
• Digital logic and physical computing

Furthermore, we expect excellent command of English, both written and oral. An open, creative and independent attitude is an important asset for both positions.

We offer the opportunity to pursue a high-quality PhD at a renowned institution in a vibrant and collaborative research group. The position also bears the opportunity for research stay the AMOLF Insittute.