MSc.Thesis Defense:Seyed Sajjad Mirbakht

SOFT AND SKIN-LIKE STRETCHABLE SILK-BASED EPIDERMAL ORGANIC BIOELECTRONICS FOR COMPREHENSIVE HUMAN PHYSIOLOGICAL SIGNAL MONITORING

SEYED SAJJAD MIRBAKHT
Electronics Engineering, MSc. Thesis, 2024

Thesis Jury

Asst. Prof. Murat Kaya Yapici (Thesis Advisor),

Prof. Fevzi Çakmak Cebeci,

Asst. Prof. Dr. Seval Kınden

Date & Time: 18th, July 2024 – 05:00 PM

Place: FENS L067

Keywords : biosignals, biomaterials, flexible electronics, silk, soft electronics

Abstract

Skin-like epidermal bioelectronics, a unique and transformative technological class, introduces highly imperceptible and mechanically akin human skin digital health units for continuous and real-time health monitoring. These innovations, stemming from advancements in novel material synthesis and fabrication techniques, offer unparalleled features such as conformability, miniature footprint, and elasticity, where such unique features not only enhance the precision of health data recording but also promote patient adoption due to its comfort and unobtrusiveness. However, existing solutions still lack desirable properties, such as self-adhesivity, breathability, biodegradability, and transparency, and fail to offer a streamlined and scalable fabrication process. We present protein-based silk-based skin-like epidermal bioelectronics to address these challenges, exploiting all the desirable material features of silk as a substrate, which have been individually present in existing devices but never combined into a single embodiment. As a significant advancement, our all-in-one solution possesses excellent self-adhesiveness (300 N/m), high breathability (1263 g.h-1.m-2), and swift biodegradability in soil within a mere two days. Additionally, possessing an elastic modulus of ~ 5 kPa and surpassing 600% in stretchability, our soft electronics seamlessly replicate the mechanics of the epidermis and form a conformal skin/electrode interface. Therefore, precisely inkjet-patterned with silver nanoparticle and coupled with a flexible readout circuitry, Silk epidermal bioelectronics is capable of real-time and non-invasively recording of electrophysiological biosignals, including cardiac (ECG), neural (EEG), muscular (EMG), and ocular (EOG), in durations reaching up to 12 hours with superior performance in par with Ag/AgCl gold standard electrodes.