Water activated disposable paper battery.

We developed a disposable paper battery aiming to reduce the environmental impact of single-use electronics for applications such as point of care diagnosis, smart packaging and environmental sensing. The battery uses Zinc as a biodegradable metal anode, graphite as a nontoxic cathode material and paper as a biodegradable substrate. To facilitate additive manufacturing, we developed electrodes and current collector inks that can be stencil printed on paper to create water-activated batteries of arbitrary shape and size.

Versatile carbon-loaded shellac ink for disposable printed electronics.

Emerging technologies such as smart packaging are shifting the requirements on electronic components, notably regarding service life, which counts in days instead of years. As a result, standard materials are often not adapted due to economic, environmental or manufacturing considerations. For instance, the use of metal conductive tracks in disposable electronics is a waste of valuable resources and their accumulation in landfills is an environmental concern.

Fully 3D Printed and Disposable Paper Supercapacitors.

With the development of the internet-of-things for applications such as wearables and packaging, a new class of electronics is emerging, characterized by the sheer number of forecast units and their short service-life. Projected to reach 27 billion units in 2021, connected devices are generating an exponentially increasing amount of electronic waste (e-waste). Fueled by the growing e-waste problem, the field of sustainable electronics is attracting significant interest.

Enzyme Activities of Five White-Rot Fungi in the Presence of Nanocellulose.

White-rot fungi can degrade all lignocellulose components due to their potent lignin and cellulose-degrading enzymes. In this study, five white-rot fungi, , , , and were tested for endoglucanase, laccase, urease, and glucose-6-phosphate (G6P) production when grown with malt extract and nanocellulose in the form of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidized cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC). Results show that temperature plays a key role in controlling the growth of all five fungi when cultured with malt extract alone.

Integrated elastomer-based device for measuring the mechanics of adherent cell monolayers.

Cells in the body collectively sustain mechanical deformations in almost all physiological functions. From the morphogenesis stage, cells' ability to sustain stress is essential for the body's well-being. Several pathologies have been associated with abnormal mechanical properties, thus suggesting the Young's modulus as a biomarker to diagnose diseases and determine their progression.

High-speed mechano-active multielectrode array for investigating rapid stretch effects on cardiac tissue.

Systematic investigations of the effects of mechano-electric coupling (MEC) on cellular cardiac electrophysiology lack experimental systems suitable to subject tissues to in-vivo like strain patterns while simultaneously reporting changes in electrical activation. Here, we describe a self-contained motor-less device (mechano-active multielectrode-array, MaMEA) that permits the assessment of impulse conduction along bioengineered strands of cardiac tissue in response to dynamic strain cycles. The device is based on polydimethylsiloxane (PDMS) cell culture substrates patterned with dielectric actuators (DEAs) and compliant gold ion-implanted extracellular electrodes.

An ultra-fast mechanically active cell culture substrate.

We present a mechanically active cell culture substrate that produces complex strain patterns and generates extremely high strain rates. The transparent miniaturized cell stretcher is compatible with live cell microscopy and provides a very compact and portable alternative to other systems. A cell monolayer is cultured on a dielectric elastomer actuator (DEA) made of a 30 μm thick silicone membrane sandwiched between stretchable electrodes.

Assessing the degradation of compliant electrodes for soft actuators.

We present an automated system to measure the degradation of compliant electrodes used in dielectric elastomer actuators (DEAs) over millions of cycles. Electrodes for DEAs generally experience biaxial linear strains of more than 10%. The decrease in electrode conductivity induced by this repeated fast mechanical deformation impacts the bandwidth of the actuator and its strain homogeneity.

Flexible Zinc-Tin Oxide Thin Film Transistors Operating at 1 kV for Integrated Switching of Dielectric Elastomer Actuators Arrays.

Flexible high-voltage thin-film transistors (HVTFTs) operating at more than 1 kV are integrated with compliant dielectric elastomer actuators (DEA) to create a flexible array of 16 independent actuators. To allow for high-voltage operation, the HVTFT implements a zinc-tin oxide channel, a thick dielectric stack, and an offset gate. At a source-drain bias of 1 kV, the HVTFT has a 20 µA on-current at a gate voltage bias of 30 V.

Dielectric elastomer actuator for mechanical loading of 2D cell cultures.

We demonstrate the use of dielectric elastomer actuators (DEAs) for mechanical stimulation of cells in vitro. The development of living tissues is regulated by their mechanical environment through the modification of fundamental cellular functions such as proliferation, differentiation and gene expression. Mechanical cues have been linked to numerous pathological conditions, and progress in cellular mechanobiology could lead to better diagnosis and treatments of diseases such as atherosclerosis and cancers.