Colour-sensitive conjugated polymer inkjet-printed pixelated artificial retina model studied via a bio-hybrid photovoltaic device

Abstract

In recent years, organic electronic materials have been shown to be a promising tool, even transplanted in vivo, for transducing light stimuli to non-functioning retinas. Here we developed a bio-hybrid optoelectronic device consisting of patterned organic polymer semiconductors interfaced with an electrolyte solution in a closed sandwich architecture in order to study the photo-response of photosensitive semiconducting layers or patterns in an environment imitating biological extracellular fluids. We demonstrate an artificial retina model composed of on an array of 42,100 pixels made of three different conjugated polymers via inkjet printing with 110 pixels/mm2 packing density. Photo-sensing through three-colour pixelation allows to resolve incoming light spectrally and spatially. The compact colour sensitive optoelectronic device represents an easy-to-handle photosensitive platform for the study of the photo response of artificial retina systems.

Nanoengineering InP Quantum Dot-Based Photoactive Biointerfaces for Optical Control of Neurons

“…For the intensity of 0.57 mW mm −2 , type I and type II biointerfaces produce -65 ± 7 mV and 175 ± 13 mV (Mean ± SD, for N = 8) photovoltages under 10 ms pulse, respectively. These numbers are promising for potential photostimulation applications considering the reported photovoltage values in a previous QD-based study that can evoke neural activity (Bareket et al, 2014), and also previous organic semiconductor-based biointerface studies that reported similar or lower photovoltage values and still effectively stimulate neurons (Gautam et al, 2014;Ciocca et al, 2020;Leccardi et al, 2020).…”

“…Different than capacitive double layer charging mechanism, the charging/discharging dynamics of photoelectrochemical current generation mechanism is dependent on the rates of electron transfer at electrode-electrolyte interface and the arrival rate of reaction ions to the interface (Merrill et al, 2005). Capacitive biointerfaces have fast charging dynamics with rise times on the order of tens or hundreds of microseconds (Ciocca et al, 2020;Han et al, 2020), whereas the decay times might be in milliseconds range (Jakešová et al, 2019). On the other hand, faradaic devices have typically longer rise/fall times due to the slower charging-discharging kinetics governed by electron transfer rate and availability of ions at the reaction site (Merrill et al, 2005;Bahmani Jalali et al, 2018b, 2019a.…”

Survey of Recent Advances in Molecular Fluorophores, Unconjugated Polymers, and Emerging Functional Materials Designed for Electrofluorochromic Use

“…This opens the possibility of using them to coat substrates that span a range of sizes. Ultimately, this is advantageous in terms of upscaling the fabrication of electrochromic devices by large-scale-processing techniques such as roll-to-roll printing [ 24 , 25 , 26 ], spray coating [ 27 , 28 ], ink-jet printing [ 29 , 30 , 31 ], and slot-die coating [ 32 ].…”

PEDOT:PSS hydrogel gate electrodes for OTFT sensors

“…Organic electronic devices for biosensors and bioelectronics have undergone rapid development in recent years. This includes the development of organic neural interfacing devices for recording brain activity, 1 the delivery of neurotransmitters for therapeutic purposes, 2 real-time stimulation of neural cells, 3 neural synaptic devices, 4 artificial retinas, 5 neuromorphic devices, 6 DNA sensors, 7 glucose sensors, 8 cortisol sensors, 9 and lactate sensors. 10,11 The applicability of organic devices to such a vast and diverse array of applications owes partly to their ability to be flexible and conformable, due to the inherent flexibility of organic semiconductors.…”