Katarina Ilić | Voltera: How do you stop a highly conductive gold ink from losing its properties when printed on a stretchable substrate?
00:08:53 - 00:11:14
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How do you stop a highly conductive gold ink from losing its properties when printed on a stretchable substrate?
Printing electronics on thermoplastic polyurethane (TPU) is ideal for stretchable, skin-conformable medical devices. However, combining materials with differing mechanical limits—such as highly stretchable silver ink and less stretchable, biocompatible gold ink—creates a major delamination and micro-fracturing challenge under tension.
To solve this mismatch, a novel reinforcement strategy is used where laser-cut PET sheets are embedded between TPU layers to match the exact pattern of the gold ink. This local mechanical constraint stops the gold electrode from overstretching while allowing the overall TPU substrate to bend and flex naturally.
The entire stack is then integrated using a thermal lamination process to seal the multi-material layers together, guaranteeing reliable electrical contact from the printed silver traces through to rivet-inserted metal snap connectors.
In this short video, you can learn:
* How to handle mechanical mismatches between highly stretchable and purely flexible inks.
* Using selectively patterned PET interlayers to arrest local strains and preserve ink conductivity.
* The lamination and mechanical fastening steps required to construct a robust wearable sensor.
📋 **Clip Abstract** This clip explains the material selection and engineering techniques used to print durable multi-material bio-sensors on TPU substrates. It details how selectively placed PET reinforcing layers prevent precious gold ink from losing conductivity when the wearable device stretches.
#ThermoplasticPolyurethane, #StrainIsolation, #ConductiveGoldInk, #ThermalLamination, #StretchableElectronics, #WearableBioSensors
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00:07:24 - 00:08:52
Why is a hexagonal labyrinth the absolute optimal design for gel-free dry bio-electrodes?
Why is a hexagonal labyrinth the absolute optimal design for gel-free dry bio-electrodes?
Dry electrodes face persistent signal-to-noise challenges due to the absence of a conductive wet gel. This segment explains how a hexagonal labyrinth pattern optimizes the ratio of surface area to material volume, significantly enhancing electrical sensitivity while minimizing the consumption of expensive precious metals like gold.
The geometry provides a highly dense network of conductive pathways that maximizes contact conformability with dynamic human skin. By eliminating the necessity of wet gels, this architectural choice avoids skin irritation and signal degradation over extended wear.
The layout is fabricated via multi-layer deposition, utilizing a stretchable silver trace base layer topped with a gold-patterned active sensing interface, demonstrating how printed electronics rely on precise spatial design to match biological interface requirements.
In this short video, you can learn:
* How hexagonal labyrinth geometries maximize skin contact density and signal sensitivity.
* Why dry geometric patterns eliminate the need for unstable, irritating wet conductive gels.
* The material savings achieved by optimizing electrode surface-area-to-volume ratios.
📋 **Clip Abstract** This clip explores the geometrical optimization of dry ECG electrodes, highlighting the benefits of a hexagonal labyrinth design for superior skin contact and signal sensitivity. It details how this structural approach minimizes material costs while bypassing the issues of traditional wet-gel bio-sensors.
#HexagonalLabyrinth, #DryBioElectrodes, #StretchableSilverTraces, #ConformableElectronics, #PrintedElectronics, #WearableBiosensors
00:12:21 - 00:13:52
Can direct-write dispensing solve the massive material waste of printing with gold nanoparticles?
Can direct-write dispensing solve the massive material waste of printing with gold nanoparticles?
Working with high-density gold and precious metal inks introduces severe material handling and rheology challenges, specifically the rapid settling of heavy metallic nanoparticles. This settling causes concentration gradients and catastrophic nozzle clogging during fine-feature dispensing.
Solving this requires dual asymmetric centrifugal mixing to homogenize the viscous paste prior to printing, combined with direct-write micro-dispensing to achieve precise volumetric control. Traditional screen printing wastes precious material scraped onto stencils, whereas direct-write systems deposit material exclusively where required.
This level of fluidic control and adaptive dispensing makes the prototyping of biocompatible sensors economically viable, allowing developers to validate designs using cheaper silver inks before committing to precious gold runs.
In this short video, you can learn:
* Mitigating metallic nanoparticle settling and nozzle clogging through dual asymmetric centrifugal mixing.
* The cost and material-saving advantages of direct-write precision dispensing over screen printing.
* Strategies for design validation using sacrificial silver inks before deploying gold.
📋 **Clip Abstract** This clip highlights the process engineering challenges of printing with expensive, high-density gold inks. It showcases how advanced mixing and direct-write volumetric dispensing prevent material waste and nozzle failures during sensor manufacturing.
#DirectWriteDispensing, #GoldNanoparticleInk, #DualAsymmetricMixing, #MicroDispensing, #PrintedElectronics, #BiocompatibleSensors