Read-out for displacement sensor in an EHT platform

Engineered heart tissues (EHTs) are a valuable approach of the Organ-on-Chip technology to model human cardiac tissue in vitro. These microphysiological models have been reported to recapitulate human heart responses more closely than 2D cell cultures [1] and are thus a promising tool for cardiac drug testing and disease modelling

A polymer-based platform for culturing and studying EHTs has been developed in ECTM at TU Delft [2] (Fig. 1). The platform consists of two elastic PDMS micropillars surrounded by an elliptic well. After seeding in the elliptic well, cardiac cells self-assemble around the micropillars and form the tissue-like structure. Mimicking the human heart, the EHT periodically contracts and as a result exerts force on the micropillars, bending them (Fig. 2a). The contraction force generated by the tissues can be measured indirectly, by correlating it with the displacement of the micropillars. To measure this displacement of micropillars a spiral capacitive sensor has been recently developed in ECTM [3]. The basic working principle of the sensor relies on the change in capacitance between planar plates of a spiral capacitor (Fig. 2b) caused by the deformation of the PDMS substrate. Due to the very small force generated by the tissue (up to 100 μN), the expected change in base capacitance is in the fF range. Detection of such a small capacitance change requires a high-precision, custom-made and portable read-out circuitry.

The aim of the project is to design and characterize a portable read-out system for measuring very small dynamic changes in capacitance of the displacement sensor for the EHT platform. The designed PCB will be used for characterization of the developed capacitive sensor and for the future cell experiments.

References:

[1] M. N. Hirt et al.,“Cardiac Tissue Engineering: State of the Art,” Circulation Research, vol. 114, no. 2, pp. 354–367, (2014)
[2] M. Dostanic et al., “A Miniaturized EHT Platform for Accurate Measurements of TissueContractile Properties,” J.Microelectromechanical Syst., 29(5), 881 (2020)
[3] M. Shojaei Baghini, “Design and Development of Integrated Displacement Sensors for Engineered Heart Tissue Platforms”, MSc thesis, TU Delft 2020

Assignment

This experimental project will involve:

• An extensive review of the related state-of-the-art in suitable read-out methods and systems;
• Design and simulation of the read-out system;
• Electrical characterization of the read-out system;
• Capacitance measurements and bemchmarking with an alternative measurement technique;
• Reporting.

Daily advisor: Milica Dostanic

Requirements

You are an ambitious hands-on master student from microelectronics. You have good communication skills in English, you are independent and also a team player. The graduation project will have a total duration of 9 to 12 months.

If you are eager to work in a motivating atmosphere with highly skilled colleagues, then send us your CV!

Contact

dr. Massimo Mastrangeli

Electronic Components, Technology and Materials Group

Department of Microelectronics

Last modified: 2021-11-10