Periodic Reporting for period 1 - Fluidic Shaping (Fluidic Shaping of Optical Components on Earth and in Space)
Reporting period: 2022-05-01 to 2024-10-31
The Fluidic Shaping project seeks to develop and demonstrate a new concept that leverages the fundamental physics of interfacial phenomena to rapidly fabricate complex optical components of any size (from millimeters to meters) with sub-nanometer surface roughness, without the need for any mechanical processing such as grinding or polishing. We term our approach ‘Fluidic Shaping’ to describe its core principle – the ability to take a volume of liquid, shape it into a desired form, and finally cure it to obtain a solid object. The method relies on negating gravitational forces that act on the liquid, which we achieve on Earth using buoyancy forces, and which can be naturally achieved in space flight. By dictating the boundary conditions of the liquid, we vary the minimum energy state of the system, and drive the liquid interface into a desired shape. The proposed project is composed of five main aims: (1) development of a theoretical framework that would describe the range of optical surfaces that could be produced and provide engineering guidelines for the rest of the project, (2) development of a stand-alone device for fabrication of high quality corrective lenses, (3) development of methods for fabrication of high precision optics, and expansion of the range of materials that could be used, (4) demonstration of in-space manufacturing of optical components, and (5) development of approaches for deployment of very large (meters) fluidic lenses.
These aims serve to put in place the basic and foundational knowledge that could enable transformative changes in multiple fields: (a) rapid prototyping of optical components – by enabling fabrication of custom, high precision optics in minutes, (b) access to corrective eyewear in low resource settings – by enabling fabrication of quality lenses without heavy infrastructure, (c) space exploration – by enabling in-space manufacturing of optics, and (d) astronomy – by enabling large space telescopes that overcome current launch constraints.
These aims serve to put in place the basic and foundational knowledge that could enable transformative changes in multiple fields: (a) rapid prototyping of optical components – by enabling fabrication of custom, high precision optics in minutes, (b) access to corrective eyewear in low resource settings – by enabling fabrication of quality lenses without heavy infrastructure, (c) space exploration – by enabling in-space manufacturing of optics, and (d) astronomy – by enabling large space telescopes that overcome current launch constraints.
- We have successfully developed a complete analytical model for the creation of ophthalmic lenses, showing that all spherical and cylindrical ophthalmic corrections can be attained by simply controlling the volume of the polymer and the frame’s eccentricity. We have experimentally validated the model and provided a complete sensitivity analysis showing the effect of real-life fabrication parameters on the resulting lens. These results are part of a manuscript we have now submitted for publication.
- We have successfully developed a method and device that allow the fabrication of corrective eyeglasses. We demonstrated the creation of complete sets of glassed which meet industry standards on optical accuracy and surface roughness. These results are part of a manuscript we have now submitted for publication.
- In collaboration with material scientists we have conducted an extensive study of polymer formulations and their suitability for fluidic shaping. We have converged to a specific formulation that exhibits superior properties, in particular with respect to its volumetric shrinkage.
- We have successfully completed a set of zero gravity experiments in which we demonstrated the creation of curved liquid mirrors under microgravity, from both liquid metal an ionic liquids.
- We have developed an experimentally validated analytical model that is able to predict the dynamics of a liquid telescope subjected to external actuation.
- We have successfully developed a method and device that allow the fabrication of corrective eyeglasses. We demonstrated the creation of complete sets of glassed which meet industry standards on optical accuracy and surface roughness. These results are part of a manuscript we have now submitted for publication.
- In collaboration with material scientists we have conducted an extensive study of polymer formulations and their suitability for fluidic shaping. We have converged to a specific formulation that exhibits superior properties, in particular with respect to its volumetric shrinkage.
- We have successfully completed a set of zero gravity experiments in which we demonstrated the creation of curved liquid mirrors under microgravity, from both liquid metal an ionic liquids.
- We have developed an experimentally validated analytical model that is able to predict the dynamics of a liquid telescope subjected to external actuation.
Blindness is often perceived as a permanent medical condition, untreatable without highly advanced medical intervention. However, millions of blindness cases result from uncorrected refractive error – a condition that can be easily treated with prescription eyeglasses. Over 90% of these cases are in the developing world7, and remain untreated due to lack of access to corrective eyewear. This is true not only for blindness, but for all severity levels of vision impairment, making refractive error the leading untreated ophthalmic medical condition4. At present, 1 billion people in the world suffer from vision impairment and lack access to corrective eyewear.
Beyond the detrimental effects on the quality of life on the individual level, untreated vision impairment has substantial societal and economic consequences, including academic underperformance and reduced literacy, reduced workplace productivity, decrease in road safety, and gender inequality. At present, these result in an annual global financial loss of $410 billion, which, due to population growth, is predicted to increase to $920 billion by 2050 – a $20 trillion loss over three decades.
While in the developed world optometry services, which include diagnosis, prescription, and lens fabrication, are widely accessible, they are scarce in the developing world. For example, there are 221 optometrists per 1M people in high income countries (Europe, North America) but only 1 optometrist per 1M people in sub-Saharan Africa. While much work has been done in the past decade in developing accessible solutions for hdiagnosis and prescription, there remains a major challenge in providing individuals with appropriate eyeglasses.
The standard methods for fabrication of eyeglasses are based on mechanical processes such as machining and polishing, or molding. These processes require significant energy and water resources, major capital investments in infrastructure, and operation by trained personnel. Such facilities are incompatible with low-resource settings, and thus attempts to satisfy the demand for eyeglasses in such regions have relied primarily on operating distribution logistics to deliver pre-fabricated lenses to the point of need7. To date, according to the World Economic Forum, all such initiatives were able to supply only a small fraction (0.3% in 2016) of the need. Given these circumstances, there is a pressing need to innovate lens manufacturing methodologies. For example, new technologies, which bring fabrication of high-quality eyeglasses close to the point-of-need, and that are appropriate for low-resource settings, have the potential of disrupting the existing modes of operation and providing a larger fraction of the population with access to corrective eyewear.
In our work we leverage the Fluidic Shaping approach to create a complete solution for fabrication of prescription lenses that eliminates the need for any machining, polishing, or molding steps. Using a device whose footprint is 20 cm x 20 cm, with an energy consumption of 25 W, a pair of high-quality lenses (diopter variation of less than 0.15 D, and surface roughness of less than 1 nm) can be produced in under 10 minutes. As illustrated in Figure 2, the entire lens fabrication process takes place within a single device that transforms a volume of liquid polymer into a lens with any combination of spherical or cylindrical corrections.
Beyond the detrimental effects on the quality of life on the individual level, untreated vision impairment has substantial societal and economic consequences, including academic underperformance and reduced literacy, reduced workplace productivity, decrease in road safety, and gender inequality. At present, these result in an annual global financial loss of $410 billion, which, due to population growth, is predicted to increase to $920 billion by 2050 – a $20 trillion loss over three decades.
While in the developed world optometry services, which include diagnosis, prescription, and lens fabrication, are widely accessible, they are scarce in the developing world. For example, there are 221 optometrists per 1M people in high income countries (Europe, North America) but only 1 optometrist per 1M people in sub-Saharan Africa. While much work has been done in the past decade in developing accessible solutions for hdiagnosis and prescription, there remains a major challenge in providing individuals with appropriate eyeglasses.
The standard methods for fabrication of eyeglasses are based on mechanical processes such as machining and polishing, or molding. These processes require significant energy and water resources, major capital investments in infrastructure, and operation by trained personnel. Such facilities are incompatible with low-resource settings, and thus attempts to satisfy the demand for eyeglasses in such regions have relied primarily on operating distribution logistics to deliver pre-fabricated lenses to the point of need7. To date, according to the World Economic Forum, all such initiatives were able to supply only a small fraction (0.3% in 2016) of the need. Given these circumstances, there is a pressing need to innovate lens manufacturing methodologies. For example, new technologies, which bring fabrication of high-quality eyeglasses close to the point-of-need, and that are appropriate for low-resource settings, have the potential of disrupting the existing modes of operation and providing a larger fraction of the population with access to corrective eyewear.
In our work we leverage the Fluidic Shaping approach to create a complete solution for fabrication of prescription lenses that eliminates the need for any machining, polishing, or molding steps. Using a device whose footprint is 20 cm x 20 cm, with an energy consumption of 25 W, a pair of high-quality lenses (diopter variation of less than 0.15 D, and surface roughness of less than 1 nm) can be produced in under 10 minutes. As illustrated in Figure 2, the entire lens fabrication process takes place within a single device that transforms a volume of liquid polymer into a lens with any combination of spherical or cylindrical corrections.