Investigation of materials and morphologies on signal qualities of a fully printed tattoo single channel PVDF transducer

Wearable sensors have transformed the ability to monitor human physiology not only in laboratory conditions but also during everyday activity. They integrate onto textiles or place directly on human skin and do not interfere with natural movement patterns during data sampling. Specifically, skin-wearable electronics must be thin and stretchable enough to closely adhere and conform to the skin to maintain stable and high signal transduction. One of the recent emerging technologies in this field is temporary tattoo paper.[1] Its applicability to directly transfer on skin proved to be a suitable platform for wearable electronics including unperceivable sensors for electromyographical (EMG) recording. Furthermore, Leitner et al. (2021) [2] have employed an epidermal EMG-tattoo electrode and a ceramic crystal transducer to demonstrate the unimpeded transmission and collection of ultrasonic waves through the material compound. Moreover, Ha et al. (2019) [3] have shown the feasibility of piezoelectric PVDF films on tattoo paper for cardiac monitoring using seismocardiography. Within this context our work investigates the effects of different processing techniques and adaptations of PVDF films, electrode materials (including PEDOT:PSS, silver and carbon inks) and temporary tattoo layer compounds on transducer oscillations characteristics. Furthermore, we compare the suitability of screen and inkjet printing approaches and effects of printed pattern morphology and geometry on an ultrasound A-mode line in a water phantom