Research is required to fully exploit printed electronics capabilities to reach more sustainable electronic and sensing systems, targeting a higher level of circularity. Additive manufacturing of eco-friendly and renewable materials is a promising approach for the development of greener electronic systems by enabling, after service life, their ecoresorbability and/or recyclability. However, this represents important scientific and technical challenges in comparison to the established technologies. The transient materials used do not match always the properties of the standard electronic materials. They are inherently reactive to the environment which can cause some issues in terms of printability and stability over time. They might require proper encapsulation, but transient materials with good barrier properties and easy processing are missing. These different factors have led so far and in general to less performing electronic devices, better suited for short life applications.

Our original approach relies on the embedding degradable metallic traces within bio-sourced substrates and dielectrics using additive manufacturing (AM) processes to generate more sustainable smart labels. We will show some examples of fully printed wireless, chipless, and RFID tags made of compostable biopolymers and recyclable paper substrates. The conductors and antennas of these systems are made from printed zinc films sintered using an original hybrid approach (i.e. patent pending). These tags embed different types of transient sensors for environmental and biochemical monitoring. An encapsulation strategy based on natural waxes has been developed to protect the transient metallisation.

Finally, we will communicate on the learnings gained from the industry and the market in framework of our startup company initiated based on this technology. We will highlighting the different challenges to meet the practical application requirements and be competitive against the established technologies. We will also address the end of life problematic in relation to regulations and the waste streams’ infrastructures.

Organic electrochemical transistors (OECTs) are key bioelectronic devices, with applications ranging from biosensors, electrophysiological monitoring, flexible electronics, etc. To date, OECTs have been designed to provide the best possible performance and long-term stability. However, the rise of transient electronics has set a new demand for bioelectronics: the need to combine stable performance under physiological conditions (e.g., humidity, temperature) with safe, controlled degradation into non-toxic products.

While tremendous advances have been made in biodegradable insulating polymers, solutions toward degradable conjugated polymers are still lacking. Recent studies showed that acid-labile imine bonds (C=N) provide degradation under hydrolytic conditions[1,2], but lead to lower mobility compared to state-of-the-art materials and often results in degradation products with known toxicity.

Inspired by recent work in degradable conjugated polymer nanoparticles[3,4], we investigated the enzymatic degradation of a conjugated polymers thin films designed for OECTs. Our work focuses on n-type donor–acceptor polymers with established performances. Here, we show that thin films degrade via the action of hypochlorous acid (HOCl), a reactive oxygen species released by myeloperoxidase: an enzyme produced by immune cells.[5]

We then used UV–Vis spectroscopy, NMR, and mass spectrometry to elucidate the degradation mechanism in presence of HOCl. High-resolution mass spectrometry coupled with machine learning analysis enabled to identify degradation products and evaluate their potential toxicity.

Overall, our results present a new concept of enzymatically degradable high performance conjugated polymers for OECTs.

In recent years, organic mixed-conducting polymers and small systems have shown great potential in bioelectronics, neuromorphic devices, and transient electronics. Current mixed conducting materials are mostly derived from pre-existing semiconductors functionalised with polar ethylene glycol side chains; however, these materials still exhibit limited biocompatibility and degradability.[1]

Therefore, we develop a computational/in silico screening pipeline to investigate the potential of bioinspired building blocks as next-generation materials for organic mixed ionic-electronic conductors (OMIECs). Leveraging sustainable design principles and predictors for electronic charge transport and aggregation/conformational order, we compare two approaches to discover potential new mixed conductors: a computational funnel and a genetic algorithm. We apply and evaluate both approaches against a chemical design space created by matching common heterocyclic conjugated building blocks (found in organic electronics) selected from literature and patent databases.[2-5] With Bioinspired (melanin-inspired, lactam, anthraquinone directives, etc)[6-9] fragments and linking the two together with hydrolysable linkers.

Our study demonstrates that, despite the bioinspired constraints of our dataset, both approaches successfully identify many potential donor-linker-acceptor (D-L-A) systems with promising features, namely a low HOMO-LUMO gap, high inter-ring planarity, and low reorganisation energy. We then down-select a few D-L-A systems and symmetrically extend their conjugation to obtain small-molecule prototypes, which show competitive reorganisation energies (down to 123 meV). We propose that this workflow could be applied to larger datasets and tailored to discover novel chemical motifs for OMIECs and other applications.

Over the past decades, significant efforts have focused on designing structurally diverse organic semiconductors to gain control over their electronic properties and processability. This has led to substantial progress in understanding how chemical structure and optoelectronic properties influence molecular packing and device performance. As electronic devices advance from portable to wearable and implantable technologies, there is tremendous potential for applications in healthcare diagnostics. However, the interaction of organic semiconductors with biological systems remains poorly understood.

In this work, we present our latest research on integrating organic semiconductors with biological systems, focusing on the material design requirements for bioelectronic applications. We demonstrate the creation of bioelectronic scaffolds embedded with therapeutic cells for peripheral nerve repair. Our constructs maintained cell viability and significantly upregulated pro-regenerative gene expression, particularly the transcription factor c-Jun, which is critical for Schwann cell repair. These bioelectronic tissue-engineered constructs aim to enhance both the therapeutic cells and the body’s endogenous nerve repair mechanisms. By incorporating electrical stimulation (ES) into the regenerative process, our system further augments nerve repair following surgical implantation of the bioelectronic scaffold. Additionally, we explore chemical modifications of organic semiconductors to optimize polymer-cell interfaces, emphasizing their effects on cell viability and proliferation. These findings are crucial for the successful integration of organic electronics with biological systems in future bioelectronic devices.

The additive manufacturing of stimuli-responsive polymers has gained increasing attention for the development of customized 3D/4D printed scaffolds that respond to biological stimuli for personalized medicine purposes. Among different biological stimuli, reactive oxygen species (ROS) have emerged as powerful cell-signaling agents in disease but also in physiology. ROS effect can vary from beneficial cell survival to non-desirable oxidative stress when they are overproduced, thus causing inflammation, cancer, and age-related diseases.[1] The controlled production of ROS through exogenous stimuli such as light is expected to provide lower invasiveness, relying on wireless stimulation, reversibility, and high spatial selectivity. Semiconducting polymers, originally used in organic electronics, are attracting increasing attention as phototriggers of ROS due to their biocompatibility, intrinsic conductivity and optical properties.[2]

In previous works, we focused on poly(3-hexylthiophene) (P3HT) materials processed in the form of thin films and nanoparticles whose performance was influenced by the π-conjugated semiconducting polymer structure and its 3D confinement during the nanomaterial formation. All those features clearly modulated the photophysical processes and ultimately determined their biophotonic applications.[3, 4] Here, we will present different strategies to modulate the ROS production through the design of 3D/4D tailor-made polymer scaffolds via digital light printing (DLP). To that aim, we designed ROS responsive hydrogels through the use of P3HT semiconducting polymer nanoparticles (SPNs), which acted as both visible-light photoinitiators and photosensitizers in 3D printable acrylic hydrogels. Interestingly, P3HT SPNs retained their photoelectrochemical properties when embedded within the polymer hydrogels, showing photocurrent densities that range from ∼0.2 to ∼1.1 μA cm⁻² depending on the intensity of the visible light-lamp (λ = 467 nm). Second, they can be used as photosensitizers (PS) to generate reactive oxygen species (ROS), 12–15 μM H₂O₂, on demand. The acrylic hydrogels containing P3HT SPNs do not exhibit cytotoxic effects under normal physiological conditions in the darkness against mouse glioma 261 (GL261) cells and S. aureus bacteria. However, they induce a ∼50% reduction GL261 cancer cell viability and a ∼99% S. aureus cell death in contact with them upon illumination (λ = 467 nm) due to the localized overproduction of ROS, which makes them attractive candidates for photodynamic therapies (PDT).[5]

The integration of electronics into ingestible systems has opened new frontiers in point-of-care diagnostics, personalized medicine, and gastrointestinal monitoring [1]. The development of completely edible devices made entirely of food-grade materials that can function inside the body without the need for surgical retrieval or posing long-term risks is one of the most promising avenues [2], [3]. A critical unmet need in this field is the realization of edible transistors with sufficiently fast and stable AC performance to support logic gates and dynamic circuits, enabling future applications such as intrabody communication (IBC).

In this work, an edible organic electrochemical transistor (OECT) operating at low voltage (<1 V), specifically designed as the active component of future edible signal generators, is presented. The transistor comprises inert gold electrodes on an edible ethyl cellulose substrate, a solution-processed copper phthalocyanine (CuPc) semiconductor, while for the gate dielectric, various edible electrolytes were formulated, deposited, and evaluated through electrochemical impedance spectroscopy (EIS).

The devices were characterized in terms of their DC transport properties, including threshold voltage, transconductance, and reproducibility. Finally, OCETs dynamic behavior was evaluated through the extraction of the transition frequency (fT), a key parameter for potential integration into low-frequency oscillators. The OECTs demonstrated operation at frequencies in the kHz range which highlights their potential for dynamic circuit applications in edible electronics. Such frequency levels are sufficient to support basic logic elements and signal modulation functions, with possible future applications including, but not limited to, IBC and real-time sensing.

Gastrointestinal fluids contain valuable biomarkers for disease diagnosis; yet current methods to access them rely on rigid devices made of potentially toxic materials and require specialized clinical settings, posing risks to both users and the environment.

We introduce an edible biosensor capable of quantifying metabolites and enzyme activity in gastric fluid, designed to be safely ingested and partially metabolized, eliminating the need for hospitalization or disposal. All materials used are fully safe for ingestion, including food additives (ethyl cellulose as substrate, gold and silver electrodes), a toothpaste pigment (copper phthalocyanine) as the semiconductor, chitosan as the electrolyte, and naturally occurring biorecognition elements (caffeic acid and horseradish peroxidase).

The biosensor is demonstrated for H₂O₂ detection, a reactive oxygen species associated with gastrointestinal inflammation, using a controlled redox reaction between caffeic acid and HRP. Following spectrophotometric and electrochemical validation, the system is integrated into an edible extended-gate electrolyte-gated field-effect transistor. In vitro testing shows H₂O₂ detection across 0–3 mM, with a limit of detection of ~144 µM and sensitivity of 2.7 µC mM⁻¹, using only 500 µL of sample and a 4-minute test time. Minimal modifications of the biorecognition elements enable detection of additional metabolites, such as glucose and cholesterol, as well as gastric peroxide enzyme activity. The biosensor was validated under simulated physiological conditions, accounting for variations in temperature, pH, and potential interfering agents.

This work represents a step toward safe, in vivo biosensing in the gastrointestinal tract that is fully edible and accessible at the point of care.

Water covers two-thirds of the Earth's surface and stores a vast amount of energy, which is responsible for making the water cycle possible. Harnessing this energy could help meet the growing demand for power while providing a sustainable source for a cleaner future. Hydrovoltaic generators, consisting of porous material sandwiched between two electrodes, are designed to convert the motion of water via charge-selective microscale channels to electrical energy. Here, we introduce leaves as a porous material for hydrovoltaic generators. By leveraging the presence of microscale channels along with the ease of functionalization, we report the development of leaf-based hydrovoltaic generators that can continuously produce high open-circuit voltage (up to 1.47 V) and short-circuit current (up to 4.68 mA/cm²) with a maximum power density of 390 μW/cm² [1], a substantial improvement over recently reported devices. We will present our study on understanding the mechanism behind hydrovoltaic electricity generation in these devices, the optimization process, and their potential applications. Utilizing leaves as sustainable bio-based active materials for high-power-density hydrovoltaic devices offers an environmentally friendly and sustainable alternative for powering up micro-power devices.

Repurposing biology for technology is one of the pathways for a sustainable future reducing synthetic waste and carbon emissions. The integration of living components directly in materials and devices opens new possibilities for energy efficient, sustainable materials that are dynamic and responsive. Previously we leveraged the biocatalytic machinery of plants for in-vivo fabrication of functional electrochemical components. Specifically, we discovered that plants polymerize conjugated oligomers in-vivo, catalysed by endogenous peroxidases, forming conductors within their structure. We then demonstrated intact plants with electronic roots that continue to grow enabling plant-biohybrid systems that maintain fully their biological processes. Apart from augmenting plants with non-native functionality we are also interested in using synthetic materials for enhancing plant processes. We developed polyethyleneimine-based nanoparticles that enhance photosynthetic biochemical reactions in-vitro while in-vivo enhance plants CO₂ capture ability. Our latest work extends these concepts to plant cells combined with additive manufacturing for producing custom made sustainable photosynthetic living materials with technological functionality.

The convergence of sustainable materials, unconventional electronics, and advanced fabrication strategies is opening new frontiers for next-generation sensing systems in agriculture and food technologies. In this invited contribution, we present a portfolio of thin, flexible, biocompatible, and—when required—biodegradable devices designed to interface directly with plants, fruits, and their surrounding microenvironments.

We begin by outlining advancements in low-impact materials and scalable, low-cost fabrication techniques that form the foundation for environmentally responsible sensing platforms. Building on these material innovations, we introduce an integrated toolbox of devices tailored for precision agriculture and fruit-quality assessment.

We first demonstrate how bioimpedance techniques, enabled by customized electrodes, portable impedance analyzers, and dedicated machine-learning algorithms, allow sensitive monitoring of both plant physiology and fruit quality. Extending beyond bioimpedance, we present printed impedimetric paper-based relative-humidity sensors that provide unobtrusive, continuous monitoring of the plant-associated microclimate, including deployment in real outdoor field conditions.

The talk then highlights printed stretchable strain sensors specifically developed for in-orchard monitoring of apple growth, enabling non-invasive, real-time assessment of fruit expansion dynamics and offering new insights for crop management and yield forecasting.

Finally, we address circular materials and biodegradable electronics derived from agricultural waste streams. Examples include conductive composites formed by combining hydrolyzed tomato plant residues with graphene nanoplatelets for biodegradable bioimpedance electrodes, and ultra-thin molybdenum-coated onion-epidermis membranes that deliver high-fidelity sensing with minimal ecological footprint. Together, these technologies illustrate that biodegradability, circularity, and high performance can coexist.

Overall, this multidisciplinary framework demonstrates how sustainable and unconventional sensing technologies can enable precision agriculture, enhance fruit-quality control, reduce resource consumption, and guide the development of eco-intelligent agri-food systems.

Precise temperature monitoring is essential for a wide range of applications including agriculture, healthcare, manufacturing, and soft robotic systems. Temperature sensors also play a key role in the calibration of other sensing devices that are temperature sensitive. As the demand for such sensors increases, concerns about their end-of-life disposal, the resulting electronic waste, and the associated environmental impact are becoming more prominent. To address this, we present a fully eco-friendly, cellulose-based resistive temperature sensor. The sensor consists of conductive graphene-based interdigitated electrodes fabricated using a laser-induced graphene (LIG) technique on cellulose acetate. LIG enables synthesis, solvent-free deposition, and low-energy patterning in a single step, offering a sustainable route for device fabrication. Further, we have utilized machine-learning approaches to optimize the lasing parameters and achieve the optimal electrical performance faster with minimal experimental trials. The sensing layer consists of a hydroxypropyl cellulose/choline chloride (ChCl) composite, whose conductivity varies with temperature, enabling reliable and sensitive detection. The use of bio-derived materials ensures material circularity, reduced environmental burden, and compatibility with end-of-life degradation pathways. Additionally, a flexible temperature-sensor array will be demonstrated to map spatial temperature distributions, highlighting the potential of the device for scalable and transient green electronics.

Current computing systems are facing two essential challenges: tremendous energy consumption due to the conventional Von Neumann architecture with low energy efficiency and environmental sustainability by depletion of nonrenewable materials, production of electronic waste, etc. One potential solution to simultaneously address these two issues is by brain-inspired neuromorphic computing with green electronic components, so that energy-efficient operation, sustainable material resources, and environmentally friendly disposals can be achieved. Such sustainable neuromorphic computing systems require hardware components not only capable of mimicking human neuron and synapse - the basic building block of biological neural networks but also made from natural organic materials such as polypeptides (proteins) and polysaccharides (carbohydrates) which are renewable, abundant in nature, biodegradable, eco-friendly, and with low-cost material and fabrication cost. In this paper, we report resistive switching random access memory (ReRAM) made from an encouraging natural organic carbohydrate material - fructose, for such emerging sustainable neuromorphic computing systems and neural networks. ReRAM has been proven to be a promising memory device technology for neuromorphic computing systems due to their ability to retain resistive states and respond to input signals in an analog or digital fashion, as well as fast speed, scaling and integration capability. Fructose resistive films incorporated with single wall carbon nanotubes (SWCNTs) were formed by a low cost solution-based process and sandwiched between bottom and top electrode, a simple metal-insulator-metal structure which is analogous to a biological synapse with presynaptic neuron (top electrode), postsynaptic neuron (bottom electrode), and synaptic cleft (fructose-CNT film). The nonvolatile memory behaviors were demonstrated by modulating the conductance by voltage stimuli applied on the fructose-CNT ReRAM device, with excitatory current flow in the device being monitored. Characteristics including bipolar resistive switching, retention, endurance cycles, long-term potentiation and depression, desolution in water, etc. are reported. All these results testify that fructose-CNT ReRAM devices are promising for energy-efficient and sustainable neuromorphic systems.

The manufacture and disposal of modern electronic devices impose a significant environmental burden, while processing large-scale sensory data requires substantial energy consumption. Achieving truly sustainable electronics therefore demands a multifaceted approach: (i) low-waste manufacturing; (ii) material selection that prioritizes green synthesis and end-of-life recyclability; and (iii) adoption of energy-efficient edge-computing architectures enabling event-driven, parallel information processing. The advances in fully additive manufacturing, sustainable materials, and neuromorphic device engineering each address one key bottleneck towards fully sustainable electronics. However, the convergence of these separate domains, tackling the problem from cradle to grave, remains a critical technological gap. In this context, we present an array of fully printed, flexible, and sustainably manufactured synaptic Organic Electrochemical Transistors (OECTs), serving as the fundamental elements for parallel, asynchronous (thus, energy-efficient) processing of a spiking neural network (SNN) for sensory data interpretation. The presented OECTs emulate synaptic behavior with high bio-plausibility. Presynaptic current pulses at the gate induce analog conductance tuning with high linearity and repeatability among OECTs. This consistency is typically hard to achieve in printed devices, for which network simulations reported in literature are based on single device characteristics, while it is crucial to achieve an SNN with high accuracy [1].

The synaptic OECTs fabrication is governed by sustainability criteria. Manufacturing is based on low-waste inkjet printing, and the material is governed by non-toxicity and green ink formulation. The material stack features a flexible bio-based ethyl cellulose substrate, electrodes printed with water-based gold inks, and a printed channel of green-synthesized Organic Mixed Ionic–Electronic Conductor (OMIEC) poly[2-(3,3′-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-[2,2′-bithiophen]-5-yl)thieno[3,2-b]thiophene] (p(g2T-TT)).

The so-fabricated synaptic OECTs exhibit analog modulation of the channel conductance in a large window (I_ON/I_OFF > 10³), demonstrating potentiation and depression analogous to biological synapses. The magnitude of the conductance change ΔG scales with pulse amplitude, duration, number, and frequency, thus implementing synaptic plasticity functions needed real-time adaptive learning. All devices show a common window of more than 40 linear conductance states (with deviation from linearity <5%). This, together with the symmetric conductance update, where potentiation and depression occur at symmetric ΔG steps of opposite sign depending on the presynaptic pulse polarity, enables easy and consistent programming, needed for an agile and accurate SNN.

These results establish the presented green, flexible synaptic OECT as a promising building block for smart bio-inspired artificial sensory systems—including electronic skins, human–machine interfaces, and soft robotics—where sustainable materials and on-device learning converge to enable intelligent, eco-friendly electronics.
 

Printing technology is set to enable the high-throughput, low-cost, and customized fabrication of flexible, stretchable or wearable optoelectronic and sensors devices. For this to become a reality, functional printing approaches should enable high device performance and industrial compatibility. However, it must also strive for the sustainable fabrication and circular design of electronics. The most direct way to mitigate negative sustainability issues in most end-of-life phases is the utilization of inherently sustainable materials and processes from the very conception of a technology. This can simplify or reduce the economic, energetic and environmental burden on regulation, recycling or recovery of electronic waste (e-waste).

In the first part of this contribution, I will present the investigation of biodegradable electrolyte systems based on gelatin, DNA, poly(lactic-co-glycolic acid) and Polycaprolactone for the fabrication of light-emitting electrochemical cells (LEC) and electrochromic (EC) devices. We will present LECs exhibiting maximum luminance over 12,000 Cd/m2 and containing > 90% ecofriendly materials. Furthermore, we will show inkjet-printed EC devices which biodegradation was certified via an independently performed ISO test. In the second part of the presentation, I will focus on the use of bio-sourced and biodegradable materials, such as melanin and cellulose, for the fabrication of Inkjet-printed humidity sensors. For melanin-based sensors we showed that the devices exhibited fast detection and recovery times (~ 0.8 ± 0.3 s) with a 170 ± 40-fold decrease in impedance for relative humidity changes from 30 % to 90 %. For the cellulose-based sensor, the relative humidity (RH) was measured by recording the impedance moduli at different frequencies. The sensor exhibits a linear response in the range between 30% RH and 90% RH. Moreover, a color change was observed for RH ≤ 30%, making it a dual mode (electrical and visual) sensor.

NDI polymers with hydrophilic glycolated side chains are promising materials for n-type mixed ionic-electronic conduction. They have been successfully incorporated in organic electrochemical transistors (OECTs) for biosensing. These materials show high performance and stability in OECTs operating in aqueous environments when a small percentage of alkylated side chains are present in the copolymer. Our goal was to create materials with similar performance that can later be degraded to facilitate the recycling of the metal electrodes. In this presentation, I will share our work on the synthesis and characterization of naphtalene diimide (NDI) copolymers bearing glycolated and carboxylic acid-protected side chains. We used varying ratio of masked carboxylic acid and glycolated side chains to optimize the performance of the materials. Next, we used a deprotection procedure to remove the alkyl side chains, revealing the carboxylic acid. We found that even a low loading of carboxylic acid, the polymer became water soluble. This solubilization process could enable the removal of the mixed conductor to achieve partially transient electronics.

Organic electronics offer unique opportunities for sustainable and transient devices, yet reproducibility and eco‑design remain critical challenges. Within the GRETA project, we present initial results on organic field‑effect transistors (OFETs) fabricated using biodegradable substrates and semiconductors synthesized via green chemistry routes. Our work highlights the often‑overlooked role of sustainable ink formulation, demonstrating that reproducibility can be achieved without compromising device performance.
We report OFETs printed on cellulose‑based substrates with inks derived from environmentally benign solvents, achieving stable electrical characteristics across multiple fabrication batches. The integration of a plastic support cage and optimized deposition parameters ensures mechanical robustness while maintaining the transient nature of the substrate. These results establish a reproducible workflow for eco‑friendly device fabrication, bridging the gap between laboratory demonstrations and scalable production.
By focusing on sustainable materials and reproducible processes, this study lays the foundation for fully printed, transient circuits and RFID tags designed with lifecycle impact in mind. The outcomes underscore the potential of organic electronics not only as high‑performance devices but also as enablers of circular design principles in next‑generation technologies.

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. However, the difference in the physical nature of soft biological elements and rigid electronic materials calls for conductive and/or electroactive materials with added biomimetic properties to bridge the gap. Soft electronics that utilize organic conjugated polymers can bring many important features to bioelectronics. Amongst the many advantages of conjugated polymers, the ability to modulate the biocompatibility, solubility, functionality and mechanical properties through side-chain engineering can alleviate the issues of mechanical mismatch and provide a better interface between the electronics and biological elements. In this talk, I will focus on our recent progress in the molecular engineering of conjugated polymers with tunable biomimetic properties, such as biocompatibility, responsiveness, stretchability, self-healing and adhesion, and their applications. In addition, I will present our recent progress in utilizing similar approaches to achieve transience in polymer electronics.

As technology becomes increasingly embedded in every facet of modern life, there is a growing imperative need to explore innovative devices and materials together with unconventional fabrication methods, especially those that leverage materials not traditionally associated with electronics. These emerging approaches offer promising solutions to the pressing challenges of sustainability and circularity brought on by the widespread presence of electronic devices.

Against this situation, our research group is dedicated to advancing responsible electronics through printed electronics techniques, incorporating materials such as graphene derivatives, metal-organic frameworks (MOFs), and other novel compounds. A key aspect of our work is the development of devices designed with minimal layering and optimized for low power consumption, both during production and throughout their operational lifespan.

This contribution highlights recent progress in responsible electronics, showcasing their integration into fully functional systems in several field applications from agriculture to healthcare that illustrate the real-world viability of these technologies.

Transient batteries are devices that, after a stable operation time, degrade at a controlled rate, ultimately leaving minimal to no trace [1]. Such batteries are useful for environmental-monitoring sensors, where the device could be biodegraded in nature at its end of life, without needing retrieval. When materials are carefully selected to be non-toxic, this approach offers a highly sustainable alternative to conventional batteries, which are typically designed for durability, resist degradation, and often incorporate environmentally harmful substances. However, transient systems are instrinsically designed for devices that cannot be retrieved at the end of their life cycle, making recycling impractical. This approach conflicts with the sustainability principles of a circular economy, which emphasize continuous reuse and recycling of materials after their initial sourcing [2].

In this work, we propose a solution to this challenge and develop a Zn-MnO₂ battery derived from waste products. The use of waste materials represents a unique opportunity to align with the principles of a circular economy. Despite increasing recycling efforts, some waste inevitably exits the valorisation loop of a circular economy. Reintroducing certain waste products into this cycle therefore not only creates value from otherwise discarded materials, but also lowers the resource loss when transient devices are degraded at their end of life. We focus on the food waste stream, as food products are bio-based and non-toxic, showing inherent potential for biodegradable devices. Specifically, we revalorize spent coffee grounds and shrimp shells waste to produce a gel-polymer electrolyte (GPE). We show that this waste-based GPE meets the requirements needed for incorporation in aqueous battery systems, with an ionic conductivity of 22 mS/cm, an electrochemical stability window of 2V and a Young’s modulus of 40 kPa. The developed GPE was incorporated in a Zn-MnO₂ pouch cell battery that achieved an open-circuit voltage of 1.37 V and completed multiple charge/discharge cycles, confirming the feasibility of this approach.

These findings highlight the potential of transforming food waste into functional battery materials, paving the way for biodegradable and environmentally responsible energy storage solutions.

Bioelectronic devices have immense potential for advancing human health by monitoring, stimulating, and interfacing with living systems; yet, realizing their full impact requires functional materials that are less invasive, more adaptive, and accessible for widespread use. Achieving this vision demands new approaches that address the entire device lifecycle: from delivery to and integration with dynamic, soft, and curvilinear targets; to maintaining stable function over operational lifetimes; and ultimately to safe degradation or removal.

In this talk, I will discuss emerging design principles for functional materials that can meet these challenges, and highlight two research stories from our lab that illustrate how lessons from the pharmaceutical sciences can be applied to the development of next-generation electronics. First, I will propose a mechanism for assembling functional implants via non-invasive delivery methods like needle injection. I will then describe our group’s development of biomolecular piezoelectric composites that combine intrinsic energy-harvesting capabilities with favorable mechanics, biodegradability, and biocompatibility, and will discuss how we balance transience with stable long-term functionality. Altogether, these materials open up new possibilities for transient, self-powered bioelectronic systems that integrate seamlessly into patients' lives.