Boston Micro Fabrication uses projection micro stereolithography (PµSL) for micro-fabrication in 3D printing. This digital micro-display technology provides stereolithography masks that work as virtual photomasks. This technique allows for rapid photopolymerization of an entire layer with a flash of UV illumination at micro-scale resolution. The mask can control individual pixel light intensity that allows control of the material properties of the fabricated structure with spatial distribution.
Projection Micro Stereolithography (PµSL) printers separate themselves from other 3D printing techniques by utilizing the benefits of both DLP and SLA technologies. PµSL involves printing in the top-down direction of SLA. Instead of using a small-spot laser, an entire image or section of the picture is cured, as in DLP. A thin membrane of plastic is used to stretch and level the uncured epoxy in the vat. This process can produce micro-sized parts at speeds much faster than traditional microfabrication methods. By using PµSL, current additive users can push and extend the limitations of traditional SLA and DLP technologies while new users can unlock capabilities within their business that were once unachievable.
We caught up with Phil Mooney, an applications engineer at Boston Micro Fabrication, to get more details on PµSL.
Design News: Tell us about the Projection Micro Stereolithography (PµSL) technology.
Phil Mooney Projection Micro Stereolithography (PμSL) is a technique that allows for rapid polymerization of a layer of liquid polymer using a flash of UV light at micro-scale resolution. The PuSL process is different from other DLP methods in that it uses high-precision optical systems, high-precision movement control, mechanical systems, and software to precisely control each pixel through a top down light source. The resin vat moves during the build, allowing larger parts to be made or an array of parts.
This process can produce micro-sized parts at speeds much faster than conventional microfabrication. By using PµSL technology, current additive users can push and extend the limitations of traditional SLA and DLP technologies while new users can unlock capabilities within their business that were once unachievable.
What are the materials involved?
Phil Mooney BMF’s open micro 3D printing material system allows you to print with our specially formulated liquid polymers or to print with the material of your choice. BMF has eight materials compatible with its microArch 3D printer line. Each material offers different properties depending on the end user’s application. Included in this roster are three biocompatible materials, an engineering-grade production material with good aging properties, a heat-resistant material that can withstand temps of 200°C, and an alumina ceramic material.
Collaborations with some the world’s largest material manufacturers, 20,000cp printing capabilities, and thousands of resins are just a few of the options that you can choose from to get the results you want based on your specific application. One such collaboration is with LOCTITE3955, a high performance halogen-free photopolymer resin that meets UL94V0 standards.
What are some examples of micro parts in use?
Phil Mooney BMF’s ultra-high precision, accuracy and resolution are essential to many verticals such as medical device manufacturing and optics and photonics. One of our biggest customers, for example, 3D prints electronic plugs using LOCTITE3955. Medical devices include endoscopes, other medical devices and optical components housing.
Do you consult with your clients to determine the parts they need? Do you make most of your products to order?
Phil Mooney We are working with many customers on applications for production. In general, we sell and manufacture the equipment. We are always willing to print a standard part free of charge as part the sales process. We have partners in many countries who print and sell BMF components.
What is the maximum size for technology and materials?
Phil Mooney The largest build envelope is 100 x 100 x 75mm, on the microArch S240, 10µm 3D printer. PμSL 3D printing incorporates advanced optics to control the pixel size down to smaller values, which directly translate to a higher resolution. Controlling the pixel down to smaller sizes allows for PμSL 3D printing technology to print at a much smaller minimum feature size (think 1 pixel = 2μm square, which means 10μm minimum feature sizes are possible), while also maintaining high precision and accuracy.