A Disposable Planar Microwave Sensor for Assessing Antibacterial Properties of Lubricant-Infused Surfaces

Pathogen transfer on medical devices and high- touch surfaces in medical facilities poses a great challenge to healthcare systems. Lubricant-infused (LI) coatings have shown promising results in preventing bacteria adhesion. This work aims to use microwave sensors to assess the bacterial repellency properties of untreated and lubricant-infused polycaprolactone (PCL) membranes by detecting Escherichia coli (E. coli) adhesion. This work introduces a sensing platform consisting of a transmission-line reader and a split-ring resonator as a disposable sensing tag. Increasing bacteria adhesion results in a down-shift of the resonant frequency due to changes in permittivity. For the untreated membranes, the proposed sensor detected a frequency shift of 8.5 MHz when bacteria adhered to the surface. The LI-coated membranes significantly reduced the bacteria adhesion, as demonstrated by a smaller frequency shift of 1.6 MHz.