Flexible Strain Sensor Based on Printed LC Tank on Electrospun Piezoelectric Nanofibers

his work presents a screen-printed LC resonant tank-based strain sensor. The resonant tank consists of a planar inductor and an interdigitated capacitor connected in parallel. The inductor was screen printed on flexible polyamide substrate and the capacitor is printed on the piezoelectric Poly-L-lactide (PLLA) nanofibers obtained by electrospinning. The resonant frequency of the tank is tuned for ~13.56 MHz. The inductors and capacitors were characterized using an impedance analyzer to evaluate the frequency characteristic of both. As the interdigitated capacitor is realized on a piezoelectric substrate the permittivity and hence the capacitance varies with the application of dynamic pressure. For the dynamic pressure, less than 2 kPa the sensitivity S 1 is 8.55 kPa -1 . The sensitivities in the range of 2-4 kPa -1 and 4-7 kPa -1 are calculated as S 2 = 31.27 kPa -1 and S 3 = 8.61 kPa -1 respectively. The fabricated flexible sensor shows the potential for wearable applications such as sub-bandage pressure monitoring while also exploiting the piezoelectric properties of PLLA to accelerate the wound healing through electrical stimulation