Sweet Electronics: Honey‐Gated Complementary Organic Transistors and Circuits Operating in Air

Abstract

readily available natural resources for the design and fabrication of "benign" electronic solutions is growing. As a result, recently, an increased emphasis has been placed on the investigation of alternative organic, green, and biodegradable electronics. [1][2][3] When the electronic technology faces the healthcare and food sector, safety of the devices becomes mandatory. The latter is particularly critical when the electronic systems are intended to explicitly interact with the inside of the human body, be ingested either along with the consumed food or pharmaceutical products. In this framework, ingestible electronics has so far achieved remarkable advances paving the way for a new era diagnostics and therapy. [4][5][6][7][8] However, ingestible systems available to date, [9] apart from their bulk design and need of post-performance recollection, have critical drawbacks manifesting primarily in the use of toxic and non disposable materials, posing hazards not only to the consumer health but also to the environment. To this end, the recently conceptualized "edible electronics" [10][11][12] envisions electronic systems fulfilling key electronic functionalities, being sustainable, nontoxic, safe for ingestion, and cost-effective at the same time. The unique feature of this emerging field lies in exploiting edible materials of different nature (e.g., food, drugs, edible metals, edible pigments, dyes, and polymers) as electronics constituents, according to their electronic properties, to provide all the necessary building blocks: conductors, insulators, semiconductors. Due to the absolute safe composition, edible devices are intended to undergo degradation within the body after accomplishing their task, what implies elimination of any potential adverse effects.Being at an emerging stage, the field is scarce in examples. Yet the feasibility of this new paradigm relies on several inspiring and rather exotic prototypes of edible, and in particular food-based electronic components, such as cheese supercapacitors, [13] broccoli microphones, [14] charcoal-based biofuel cells, [15] silk sensors, [16] transistors based on edible pigments, [12,17] among others.In order to fulfill the fundamental electronic duties of tracking, monitoring, sensing, and data transmission, edible electronics systems will require active circuits. In this context, transistors represent the backbone components of future edible systems, for which low-voltage/low-power operation is mandatory.Sustainable harnessing of natural resources is key moving toward a newgeneration electronics, which features a unique combination of electronic functionality, low cost, and absence of environmental and health hazards. Within this framework, edible electronics, of which transistors and circuits are a fundamental component, is an emerging field, exploiting edible materials that can be safely ingested, and subsequently digested after performing their function. Dielectrics are a critical functional element of transistors, often constituting their major volume. Yet, ...

An Electrically Conductive Oleogel Paste for Edible Electronics

“…[17] Edible electronics aim to bridge ingestible with green electronics and shift from swallowable to fully digestible and not hazardous components. [18] Therefore, their implementation will ensure a safe administration without medical supervision and enable point-of-care testing since the device will safely degrade in the body/environment after performing a specific task. [17] Edible electronics envision realizing all the passive and active electronic components exploiting food derivatives with green and large-scale production methods and enabling sustainable, safe, and cheap devices.…”

“…[17,[19][20][21][22][23][24][25][26][27][28][29] Edible conductors and semiconductors that are not simply ingestible, but are non-toxic, and with good and stable performances are extremely challenging to be developed. [18,[30][31][32] Studies and technologies entirely dedicated to designing and advancing edible conductors and semiconductors with the features required for edible electronics are rare. Nevertheless, these classes of materials are necessary to enable all the edible passive and active electronic components.…”

“…[42][43][44][45] Magnesium [46] and silver [47] were applied as electrodes for current collection in edible and biodegradable triboelectric nanogenerators. Silver and gold thin films are implemented in miniaturized electronic devices such as honey-gated transistors [18] and transferable on food/pills. [17] Low quantities of gold are also used as current collectors for cheese- [48] and gelatin- [49] based supercapacitors.…”

Thermally Degradable Inductors with Water-Resistant Metal Leaf/Oleogel Wires and Gelatin/Chitosan Hydrogel Films

“…Moreover, current research is targeting their use for detection of disease-specific indicators, such as intestinal gas and gastrointestinal bleeding and for medication adherence. , Although they are unique device technologies, a concern is the risk of blockage in the GI tract due the size of the devices . To mitigate this risk, ingestible devices should use human-friendly materials. − To date, biocompatible , and conductive ingredients , have been studied for ingestible, implantable, or wearable electronic components, such as inductors, − capacitors, ,− transistors, , piezoelectric elements, batteries, and electrodes . Some ingestible sensors have shown a pH response on a sugar-based substrate, and a dietary sensor that attaches to food with silk has been reported .…”

“…12 To mitigate this risk, ingestible devices should use human-friendly materials. 13−16 To date, biocompatible 17,18 and conductive ingredients 19,20 have been studied for ingestible, implantable, or wearable electronic components, such as inductors, 21−25 capacitors, 19,26−29 transistors, 30,31 piezoelectric elements, 32 batteries, 33 and electrodes. 34 Some ingestible sensors have shown a pH response on a sugar-based substrate, 19 and a dietary sensor that attaches to food with silk has been reported.…”