|MELLONI FILIPPO||Cycle: XXXIII |
Tutor: FIORINI CARLO ETTORE
Advisor: NATALI DARIO ANDREA NICOLA Major Research topic
:Implantable and Ingestible Devices: New Opportunities for Electronics and Human Body InteractionAbstract:
The area of Biomedical Engineering dealing with the integrations of electronic technologies with the human body is increasingly gaining relevance and has long since revolutionized the process of doing therapy and diagnosis.
Special attention is reserved to the class of portable devices designed to operate within the body, in direct contact or in close proximity with the region of interest. This intimate interaction with body tissues guarantee a satisfactory device operation both as actuating and monitoring system, extending the treatments to areas that would not be accessible with wearable or non-invasive equipment. The development of these technology often crosses with the organic chemistry field leading to the integration of polymeric materials in the device architecture, chosen for their biocompatibility, flexibility and biodegradability properties, essential to establish an high affinity with biological tissues.
This dissertation collect a thorough study on the opportunities for the integration of invasive and semi-invasive electronics devices within the human body. From the design of a strain sensor for chronic medical devices implantation to the characterization of solid electrolyte gated transistors toward a transient, ingestible and edible electronics.
In particular, part of the work was focused on the development of a proof‐of‐concept implantable device for monitoring the volumetric changes of the human bladder, where the sensing element is based on a capacitive linear encoder integrated with a passive wireless radio‐frequency resonator, which can be remotely interrogated. The device proposed aims to improve the life quality of patient affected by lower urinary tract dysfunctions by providing feedbacks about the bladder filling state and so partially recovering the organ functionality.
Moving toward less invasive applications, much effort has been spent on the study of novel materials and electronics components to be introduced in the wider context of edible electronics. In this framework edible and biodegradable materials has been used for the fabrication and characterization of solid-electrolyte gated transistors. The results here presented solve some of the problems highlighted by the recent “edible electronics” literature, proposing devices able to operate in a low-voltage range (Vgs<700mV), in a high humidity environment (approaching the dew point) and with a shelf live over 100 days. Moreover, the devices were fabricated limiting as much as possible the use of toxic solvents and inert materials, with explorative experiments that led to the fabrication of fully degradable and fully printed devices on flexible and edible substrates. All these results represent a step toward a fully transient and edible electronics suitable to operate in the gastro intestinal tract.