Dec 5, 2024
8:00pm - 10:00pm
Hynes, Level 1, Hall A
Josephine Tumwesige1,Dushanth Seevaratnam1,Elizabeth Hall1,Ronan Daly1
University of Cambridge1
The widespread adoption of smart mobile technologies has revolutionised daily life, yet their potential for addressing global challenges remains largely untapped. In particular, the potential for affordable sensing, recording and communicating data with a capacitive touchscreen has been identified but is underexplored [1, 2], with no definitive studies into fringe field control for selective and quantitative sensing applications.
This presentation studies the direct-write fabrication of multiple capacitive sensing structures, including a range of coplanar interdigitated structures and two-layer variations of the Manhattan and diamond structures, as found in current mobile technologies. We carefully tune electrode dimensions, spacings and electrical behaviours through a combination of direct-write techniques, such as functional inkjet printing, aerosol printing, and laser ablation techniques. We couple detailed analyses of these surfaces with simulations and experimental sensing results to provide new insights into the links between structure, resulting fringe fields and key sensing parameters. This allows us to dramatically improve response time and sensitivity to target electrolytes, suggesting an exciting unexplored potential for numerous applications.
Our findings show that micromolar sensing can be readily achieved with simple, direct deposition of water droplets onto touchscreen sensors, which is ideal for environmental and agricultural monitoring applications looking at harmful metal ion contamination or nutrient level detection. The tuneability and link to smart mobile technologies open the door to using affordable and existing technologies for real-time, in-situ analysis with simple integration into existing digital communications and analysis techniques, enabling widespread adoption and impact.
[1] Diming Zhang, Qingjun Liu. Biosensors and Bioelectronics, 75, 273 (2016).
[2] Sebastian Horstmann, Cassi J. Henderson, Elizabeth A.H. Hall, Ronan Daly. Sensors and Actuators B: Chemical, 345, 130318 (2021).