SBIR Phase II: Low-cost polymer films for foldable cover lenses used in flexible displays

The broader impact of this Small Business Innovation Research (SBIR) Phase II project is to provide the $4B/year cover lens market an economically viable material for the upcoming form-factor it must address: foldable displays. While this market size currently represents displays that employ rigid LCD or OLED technologies, major handset manufacturers are looking to move to highly differentiated form-factors such as foldable phones to gain market share in the competitive flagship smartphone tier. To do so, the entire display module must be foldable and one of the last components to allow for this behavior is the cover lens. Foldable displays therefore must eliminate hard, brittle materials such as glass and utilize materials with the same excellent scratch-resistant properties of glass, but with the flexibility and durability under folding of polymers. This project develops a novel polysulfide thermoset for this application. This Small Business Innovation Research (SBIR) Phase II project aims to develop the first low-cost, high-performance foldable cover lens technology using polysulfide thermosetting polymer films. Currently, the amorphous polysulfide thermosets can yield the excellent optical properties and folding durability required for application in foldable display technologies. However, these materials are as of yet unable to meet the strict hardness requirement set by manufacturers looking to replace rigid glass cover lenses. In this work, the expansion of the polysulfide thermoset family of materials will be undertaken to introduce chemical and physical modifications which allow for the resultant thermosetting films to possess the requisite hardness. The resultant resin materials will then be converted using standard wet-film extrusion and curing tools commonly found in the printing industry, allowing for cost-competitive production of the resulting films. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.