Functional Devices for Healthcare Applications Based on Biological-to-Electrical Signal Transduction

Traditional biomedical measurement systems used for clinical care and research are limited as they are mostly episodic, and therefore cannot capture the day-to-day fluctuations that frequently affect patients across different therapeutic areas. In this regard, a new class of point-of-care non-invasive biomedical devices that rely on electrical signals arising from biological processes could enable a step change in automated health monitoring, disease screening and patient care, by providing a viable means to continuously monitor physiological signals of interest. This can be achieved by directly integrating functional materials that are electrically responsive to biological stimuli into wearable sensors using state-of-the-art additive manufacturing methods. This work focuses on the development of printed and flexible functional devices and sensors for electrical analysis of body fluids, forces and sounds. For example, impedance spectroscopy is used to analyze fluids within microfluidic channels for the rapid characterization of bodily fluids such as sweat via a novel frequency-based analysis method that makes use of electrodes embedded directly in the channels [1]. Similarly, a novel capacitive force sensing method based on microfluidic devices with integrated aerosol-jet printed interdigitated electrodes is shown to give rise to conformable and robust force sensors that can enable precision joint replacement surgery [2,3]. Last but not least, electrospun piezoelectric fiber-based devices are shown to have applications as acoustic sensors, whereby the functional materials properties and device geometry can be optimised for continuous observation of cardiovascular and respiratory functions via piezoelectric output measurements. These types of functional devices offer fundamental insight into the coupling of biology and electronics for applied outcomes in healthcare.

[1] “Purely electrical detection of electrolyte concentration through microfluidic impedance spectroscopy”, T Wade, S Malik, L Ives, N Catic, S Kar-Narayan, Cell Reports Physical Science 5, 102133 (2024).

[2] “Aerosol-jet-printed, conformable microfluidic force sensors”, Q Jing, A Pace, L Ives, N Catic, V Khanduja, J Cama, S Kar-Narayan, Cell Reports Physical Science 2, 100386 (2021).

[3] “Conformable and robust force sensors to enable precision joint replacement surgery, L Ives, A Pace, F Bor, Q Jing, T Wade, J Cama, V Khanduja, S Kar-Narayan, Materials & Design 219, 110747 (2022).