PhD - Leuven | More than two weeks ago
Although ultrasound is widely used in biomedical imaging, acoustic manipulation of fluids and particles on the micro to nanoscale is still at research level. Acoustic streaming represents one of the techniques to generate of flow in microfluidic devices. It has been demonstrated that accurate design of this acoustic actuator could lead to a more compact and efficient way for generating a flow in micro channel.
Since decades, imec is leading the development of novel MEMS technologies such piezoelectric and capacitive MEMS ultrasound transducers based on CMOS-compatible Silicon technology as well as surface acoustic transducer. Due to the increasing interest in producing large arrays of such sensors, imec recently developed innovative polymer ultrasound transducers using the Large Area Electronics (LAE) thin-film technology platform which allows to produce passive and active components in thin-film frameworks with world-leading performance and in flexible form factors.
In this PhD thesis, the goal is to study the interaction between acoustic waves and the fluid flowing inside a microchannel. The acoustic field will be generated by different types of ultrasound transducers. The first one is the InterDigitated Transducer (IDT) which creates a Surface Acoustic Wave (SAW) propagating at the surface of a piezoelectric layer. This IDT can be placed outside or inside the microfluidic channel as shown in the picture below. The second acoustic actuator is the Piezoelectric Micromachined Ultrasound Transducer (PMUT). PMUT are based on the flexural motion of a thin membrane coupled with a thin piezoelectric film. The goal of the PhD thesis will be to design these different actuation mechanisms. Then the candidate will implement it using a specific imec technology. After fabrication, the efficiency of the new acousto fluidic actuator will be characterized.
Figure 1: Acoustically driven micro-channel by IDT in a) and b) and by PMUT in c)
You are a highly motivated student, with background in nano-engineering, physics, material science, electrical engineering, or related. You have an interest in the ultrasounds and micro-fluidics. It is expected that you will present results regularly. You are a team player and have good communication skills as you will work in a multidisciplinary and multicultural team spanning several imec departments. Given the international character of imec, an excellent knowledge of English is a must.
Required background: nano-engineering, physics, materials science or electrical engineering with strong affinity for device physics
Type of work: 15% literature study, 30% modeling, 20% design, 35% characterization
Supervisor: Paul Heremans
Co-supervisor: Xavier Rottenberg
Daily advisor: Veronique Rochus, Ben Jones
The reference code for this position is 2021-098. Mention this reference code on your application form.