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Provided are flexible color filters and methods of manufacturing flexible color filters. An example flexible color filter comprises a transparent flexible substrate comprising a thermoset thiol-click polymer. An example method of manufacturing a flexible color filter comprises dispensing a release layer on a stiff carrier substrate; dispensing a polymer resin on the release layer; curing the polymer resin into a transparent film; fabricating a flexible color filter on the transparent film; and removing the flexible color filter from the release layer and stiff carrier substrate.

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Provided are microelectronics substrates and methods of manufacturing and using the microelectronics substrate. An example of a microelectronics substrate includes a carrier, a silicate bonding layer, and a flexible substrate, wherein the flexible substrate is bonded to the silicate bonding layer. The microelectronics substrate comprises a peel strength between the flexible substrate and silicate bonding layer; wherein the peel strength between the flexible substrate and the silicate bonding layer is below 1 kgf/m.

Overcoating materials for the planarization of display module subassemblies such as the thin‐film transistor (TFT) array or the color filter (CF) sub‐pixels have seen little innovation in the previous decade. However challenges with existing overcoat materials still exist, principally in the form of high solvent contents, difficult to remove or toxic solvents and inadequate planarization performance. In response, Ares Materials has employed its Pylux™‐brand polysulfide thermoset (PST) resins as effective overcoat materials which solve the previously described commercial overcoat material issues. In this paper we describe the use of Pylux PST overcoating resins and their corresponding planarization performance over a commercial CF, showing equivalent or improved planarization performance of < 0.2 µm while using > 2X less solvent.

A new material, ATB, is demonstrated as a temporary bonding layer for a poly(amic acid)‐based, solution‐cast polyimide and Pylux‐MF, a polysulfide thermoset. Both films are deposited atop carriers coated with ATB and after device definition, are removed from the carriers using a 90° tensile peel with peel strengths below 10 cN/cm.

This chapter discusses the basics of how materials behave under a mechanical load and shows how to compare among materials given available reference values. It presents how the properties of materials are intimately tied to the properties of the surrounding environment, the amount of load applied, and the frequency of the applied load. Many different companies make load frames and Universal Testing Machine (UTM) components with some variation on the underlying science. The chapter focuses on mechanical characterization relative to the tool used and reviews the power of structure-property relationships that can be gleaned with macroscopic and microscopic mechanical testing. It also focuses on uniaxial loading in tension and compression and provides more complex deformation modes in which are seen in dynamic mechanical analysis (DMA). In DMA, an oscillating force is applied to a material at a known frequency in a known sample geometry and the resulting strain stress and strain are calculated.

Provided are methods and systems for manufacturing and using heat-shrink elastomeric. An example method of manufacturing a heat-shrink elastomeric element comprises providing a thermoplastic elastomeric element having a first shape; modifying the thermoplastic elastomeric element to produce a thermoset elastomeric element having the first shape; heating the thermoset elastomeric element to a temperature of at least the glass transition temperature of the thermoset elastomeric element; adjusting the first shape of the thermoset elastomeric element to produce a second shape with at least one dimension greater than that of the first shape; and cooling the thermoset elastomeric element to a temperature below that of the glass transition temperature of the thermoset elastomeric element to produce the heat-shrink elastomeric element.

A bulk substrate for stretchable electronics. The bulk substrate is manufactured with a process that forms a soft-elastic region of the bulk substrate. The soft-elastic region includes a strain capacity of greater than or equal to 25% and a first Young's modulus below 10% of a maximum local modulus of the bulk substrate. The process also forms a stiff-elastic region of the bulk substrate. The stiff-elastic region includes a strain capacity of less than or equal to 5% and a second Young's modulus greater than 10% of the maximum local modulus of the bulk substrate.

Provided are flexible electronics stacks and methods of use. An example flexible electronics stack includes a flexible polymeric substrate film and a rigid inorganic electronic component. The flexible polymeric substrate film includes a thermoset polymer prepared by curing a monomer solution; wherein the monomer solution comprises about 25 wt % to about 65 wt % of one or more thiol monomers and from about 25 wt % to about 65 wt % of one or more co-monomers.

Novel and advantageous backplanes, which include a thermoset polymer substrate, are provided. The substrate can be flexible, and the polymer of the substrate can be made by mixing multifunctional thiol monomers and specifically chosen co-monomers. The monomers and co-monomers can undergo a thiol “click” chemistry reaction to form a low-cure-stress polymer network that can be used as the substrate for an electronics backplane.

Intracortical probe technology, consisting of arrays of microelectrodes, offers a means of recording the bioelectrical activity from neural tissue. A major limitation of existing intracortical probe technology pertains to limited lifetime of 6 months to a year of recording after implantation. A major contributor to device failure is widely believed to be the interfacial mechanical mismatch of conventional stiff intracortical devices and the surrounding brain tissue. We describe the design, development, and demonstration of a novel functional intracortical probe technology that has a tunable Young's modulus from ∼2 GPa to ∼50 MPa. This technology leverages advances in dynamically softening materials, specifically thiol‐ene/acrylate thermoset polymers, which exhibit minimal swelling of < 3% weight upon softening in vitro. We demonstrate that a shape memory polymer‐based multichannel intracortical probe can be fabricated, that the mechanical properties are stable for at least 2 months and that the device is capable of single unit recordings for durations up to 77 days in vivo. This novel technology, which is amenable to processes suitable for manufacturing via standard semiconductor fabrication techniques, offers the capability of softening in vivo to reduce the tissue‐device modulus mismatch to ultimately improve long term viability of neural recordings. 

Thiol‐click reactions lead to polymeric materials with a wide range of interesting mechanical, electrical, and optical properties. However, this reaction mechanism typically results in bulk materials with a low glass transition temperature (Tg) due to rotational flexibility around the thioether linkages found in networks such as thiol‐ene, thiol‐epoxy, and thiol‐acrylate systems. This report explores the thiol‐maleimide reaction utilized for the first time as a solvent‐free reaction system to synthesize high‐Tg thermosetting networks. Through thermomechanical characterization via dynamic mechanical analysis, the homogeneity and Tgs of thiol‐maleimide networks are compared to similarly structured thiol‐ene and thiol‐epoxy networks. While preliminary data show more heterogeneous networks for thiol‐maleimide systems, bulk materials exhibit Tgs 80 °C higher than other thiol‐click systems explored herein. Finally, hollow tubes are synthesized using each thiol‐click reaction mechanism and employed in low‐ and high‐temperature environments, demonstrating the ability to withstand a compressive radial 100 N deformation at 100 °C wherein other thiol‐click systems fail mechanically.

Softening microelectrode arrays, or flexible bioelectronic systems which can dynamically change modulus under the application of an external stimulus such as heat or electromagnetic radiation, have been of significant interest in the literature within the previous decade. Through their ability to actively soften in vivo, these devices have shown the capacity to attenuate the neuronal damage associated with insertion of rigid microelectrode arrays into soft tissue. Thiol-click substrates specifically have shown particularly impressive results for fabricating devices requiring small-scale, high-performance electronics for neural recording. However, previous attempts to engineer increasingly lower-modulus substrates for these devices have failed due to the fundamental chemistries' (the thioether linkage) flexibility. This failure has led to substrates without sufficient mechanical rigidity for penetrating soft tissue at physiological temperatures, or sufficient softening capacity to reduce the mechanical mismatch between soft tissue and implantable device. In this work, a ternary thiol–epoxy/maleimide network is investigated as a potential substrate materials space in which the degree of softening can be modulated without sacrificing the mechanical rigidity at physiological temperatures. Using these networks as platforms for the microfabrication of electrode arrays, example implantable intracortical microelectrode arrays are fabricated on both thiol–epoxy and thiol–epoxy/maleimide networks to demonstrate the insertion capacity of microelectrode arrays on the ternary polymer networks.

© 2020 by Radu Reit, Ph.D.