Eindhoven University of Technology (TU/e,
www.tue.nl) is a world-leading research university specializing in engineering science & technology. Within the Electrical Engineering Department, the Integrated Circuits group (
https://www.tue.nl/en/research/research-groups/integrated-circuits/) focuses on analogue and mixed-signal circuit design for front ends, including AD and DA conversion and RF front-ends. The IC group is recognized in the academic world as one of the leading research centres in integrated circuits design in Europe. The EE department strives for societal relevance through an emphasis on the fields of smart sustainable systems, the connected world, and care and cure. The TU/e is the world's best-performing research university in terms of research cooperation with industry (#1 since 2009).
The Smart-Sense projectElectronics made with metal-oxide thin-film transistors (TFTs) can be processed with high throughput at near-to-ambient temperature on inexpensive plastic films: it is thus emerging as a high-potential technology to make electronics at ultra-low cost per area.
Smart-Sense will focus on designing sensing systems built by using advanced a-IGZO transistors. The circuit blocks will be designed at TU/e and will then be manufactured on flexible foils in Eindhoven by our project partner Holst Centre/TNO. Two IC design PhD positions are available in the project.
The first PhD will design novel interfaces between the brain and electronics that are comfortable to wear and can be single-use. Examples include EEG systems with a large number of channels.
The second PhD will design sensor systems where the increased speed of new a-IGZO transistors is exploited for unprecedented applications like ultrasound (US) imaging on a flexible foil and cell monitoring in a solution via impedance spectroscopy.
The main challenges to be addressed in this project include:
- The large 1/f noise and parasitic capacitances of a-IGZO TFTs, which have an impact on SNR and input impedance of biomedical frontends based on this material;
- The limited transition frequency of these transistors and their limited matching and accuracy, which typically limit the SN(D)R achievable in analogue to digital conversion circuits;
- The difference in supply voltage between a-IGZO and conventional Si integrated circuits, that make challenging the integration of these technologies in a system.
The results expected from the Smart-Sense research are:
- A scalable IGZO TFT model, including an accurate description of frequency and noise behaviour;
- An a-IGZO biomedical front-end designed for EEG applications optimized for noise efficiency, CMRR and PSRR, with an input impedance in excess of 100MΩ and less than 25mm2 footprint;
- An a-IGZO analogue to digital converter with dynamic range exceeding 70dB and bandwidth above 3kHz;
- A prototype single-use EEG measurement foil designed with a-IGZO transistors and including a custom periphery Si IC for signal processing and conversion to digital format;
- A prototype flexible US sensor exploiting a-IGZO custom-designed circuits.