Karl Martinson, director of business development for North America, micrometal Etching Group
This article looks at how the characteristics of micrometal’s photo-chemical etching (PCE) process allow for the manufacture of very thin metal filters with hole geometries that can be varied within a single pattern. Such filters can be produced for a variety of light and sound management applications.
Photochemically etched filters in continuous strips, ready to be cut to size for specific applications.
Light management
Light transmission and attenuation, especially angle-dependent, can be difficult to manage depending on the size limitations and space constraints available. Our PCE process can be used to produce very thin metal panels that transmit, attenuate, block and even focus or re-direct light depending upon incoming angle, all with no moving parts or power requirements. Light transmission of up to 90 percent and near-complete attenuation can be achieved in the same panel, and creative design options can enable unique manipulation of light.
Thin filters with holes of varying angles, shapes and patterns crafted through PCE offer solutions for advanced light management. The ability to design holes with multiple geometries and angles within a single pattern or array on a panel enables the manipulation of light in complex and highly specific ways. For example, varying hole angles can influence the directionality of light, allowing for beams to be blocked, refracted or reflected in targeted directions. Also, different hole shapes and patterns can control the intensity, diffusion and spread of the transmitted light. A great example is lamination of these types of panels on top of or within window glass, where sunlight can be blocked at peak times of day and allowed to pass at others, minimising heating and cooling costs.
These filters can also be used in optical systems, displays or advanced lighting setups to provide tailored illumination profiles, precise beam shaping and controlled light dispersion. The ability to have diverse hole shapes and angles within one pattern can also be critical in applications such as spectrometry, where light must be separated into its constituent wavelengths in specific patterns.
PCE is an ideal technology for producing such intricate filters due to its exceptional precision and adaptability. Unlike mechanical methods, which can struggle with maintaining precision over complex patterns, PCE uses a chemical process that can faithfully reproduce even the most intricate designs without inducing mechanical stress or deformation. The process is also burr-free, ensuring that the edges of the holes are clean, which is crucial for precise light management. Furthermore, PCE can handle diverse metals, granting designers the flexibility to select materials based on their individual mechanical properties. These advantages make PCE a go-to choice for creating high-transmission thin-wall filters with multifaceted hole configurations for sophisticated light management applications.
Thin-wall filters with intricate hole geometries can be employed to create light patterns on surfaces or visual effects. When sunlight or artificial light sources pass through these filters, the variable angles, shapes and patterns of the holes dictate how the light will be dispersed or concentrated upon emerging from the filter. This means a myriad of patterns or effects can be achieved on the receiving surface, ranging from focused beams to intricate shadows or diffused light gradients. The diversity of hole designs within a single filter can further enrich the resultant patterns, enabling the creation of complex and dynamic visual experiences. Such capabilities can be advantageous in architectural designs for decorative illumination, in theatrical productions for mood lighting or even in commercial spaces where lighting can enhance branding or ambiance. The precision and customisation offered by these filters make them powerful tools in the hands of designers and artists looking to harness light in impactful ways.
In addition, closely spaced, photochemically etched precision holes in filters can serve as locators or guides for microlight sources in high-resolution displays. Such configurations can be instrumental in microLED or miniLED display technologies where individual tiny LEDs act as the pixels. By aligning each microLED with the precisely etched holes, designers can ensure uniformity in light emission, optimise pixel density and achieve tight control over each light source. This precision alignment becomes particularly critical in high-resolution displays where the spacing and consistency of microlight sources directly influence the display’s clarity, colour accuracy and overall performance. In essence, filters with closely spaced holes can act as templates or frameworks, facilitating the meticulous arrangement of microlight sources required in cutting-edge display technologies.
Lastly, the fact that our PCE process can work with thin-sheet metal materials is another significant advantage in the creation of filters for light management. The inherent flexibility and minimal thickness of these materials allow the filters to seamlessly adhere to curved surfaces, expanding the scope of their applications. The ability to conform to non-linear and intricate designs is invaluable for automotive display, wearable technology or architectural lighting applications. The slim profile of these materials ensures that they occupy minimal space, making them particularly suited for compact devices or installations where bulkiness could compromise functionality or design integrity.
Cross-section hole shapes and geometries that can be achieved using photochemical etching (PCE).
Sound management
Ok, we hear you, so what about managing sound? We certainly believe that filters crafted with precise holes and patterns, similar to those discussed for light management, can be used in acoustic applications. When applied to sound waves, these filters can act as acoustic meta-surfaces or diffusers, selectively attenuating or redirecting sound from specific angles.
The intricacy of the hole patterns can influence the manner in which sound waves interact with the filter, allowing for the manipulation of acoustic wavefronts. By strategically designing these filters, it becomes feasible to sculpt the acoustic landscape, isolating or emphasising sounds from particular directions or frequencies. Such capabilities can be pivotal in environments that demand precise acoustic control, such as sound studios, concert halls or noise-sensitive industrial settings. So, while primarily conceptualised for light, the versatile design principles behind these filters can be repurposed for sound modulation.
It is also possible that thin-wall filters with meticulously crafted hole geometries and through angles could have a pronounced effect on sound wave propagation, particularly in distinguishing between different frequencies. Depending on the size, shape and orientation of the holes, these filters could act as selective barriers, allowing specific frequencies to pass while deflecting or attenuating others. For instance, larger hole dimensions might allow lower frequencies to pass, whereas intricate or smaller hole geometries might deflect or attenuate them. Conversely, higher frequencies, with their shorter wavelengths, could either be allowed to pass or be attenuated based on the hole characteristics. The through angle or orientation of the holes could further influence the directionality of both incoming and outgoing sound waves, enabling the redirection of specific frequencies. This frequency-selective behaviour, achieved through tailored filter designs, could be invaluable in applications such as acoustic engineering, speaker design and noise control, offering a nuanced approach to sound management.
Indeed, thinking outside the box, high-transmission thin-wall filters could be hidden behind surfaces such as wall panels and ceilings. Despite being concealed, the precision-engineered holes and through-angles of the filters would be able to actively influence sound wave interactions, attenuating certain frequencies, redirecting sound waves or enhancing specific acoustic characteristics. This hidden integration would allow the desired acoustic performance to be achieved without compromising design aesthetics of a space. Such an approach could be especially valuable in environments such as theatres, conference rooms or residential settings.
I hope to have stimulated some ideas on where micrometal’s PCE process could be used to control sound. We would be happy to hear your thoughts and work with you to develop a bespoke solution.
micrometal