Interview with Craig Rosenblum: 3D Printing Post Processing

Craig Rosenblum is the President of Himed. Over 30 years of operation, Himed has become a global leader in calcium phosphate-based biomaterial production and has developed proprietary plasma spray coatings and surface treatments. Craig and his team collaborate directly with dental and medical device manufacturers worldwide to provide innovative biomaterial solutions. Craig discovered a unique application for MATRIX MCD® post-processing additively manufactured titanium implantable devices using Himed’s proprietary and biocompatible resorbable blast media. Himed has since formed a strategic partnership with Lithoz, a global market leader in 3D printing, to develop new bioceramic bioinks for medical 3D printing. Craig received his B.S. and M.S. degrees in Materials Science & Engineering with a Biomaterials concentration from Johns Hopkins University (Baltimore, MD). With a focus on biomaterials characterization, his groundbreaking research explored the variations in dental enamel’s microstructure and mechanical properties. These studies were the first to demonstrate the unique heterogeneous nature of enamel. Craig serves on The Johns Hopkins University Materials Science & Engineering Advisory Board.

Craig will speak at our in-person/hybrid event on Feb 12, 2024, focusing on 3D technologies in the orthopedics space before AAOS 2024.

Pictured is the complex enamel orientation of water voles (Arvicola amphibius), the only known species with three distinct enamel types (radial, lamellar, tangential) as characterized by prism orientation. The materials properties of this enamel are quite different from human enamel and of particular interest to anthropologists. (Photo Credit: Craig Rosenblum)
Pictured is the complex enamel orientation of water voles (Arvicola amphibius), the only known species with three distinct enamel types (radial, lamellar, tangential) as characterized by prism orientation. The materials properties of this enamel are quite different from human enamel and of particular interest to anthropologists. (Photo Credit: Craig Rosenblum)

Jenny: When was the first encounter you had with 3D printing? What was that experience like? What were you thinking at that moment?

Craig: I first encountered 3D printing during my undergraduate and graduate studies, however, the term initially seemed very abstract. My first memorable encounter was at the Medical Device & Manufacturing East expo in New York City. In an effort to demonstrate additive manufacturing more concretely, one of the exhibitors was 3D printing intricately designed pancakes, layer by layer, directly onto a griddle! 

Years later as the technology continued to improve and print resolution increased, it has been quite remarkable to see more complex designs. When I joined Himed in 2015, my first engineering project was to develop a porous titanium plasma spray coating in atmospheric conditions. This patented technology could create interconnected porosity throughout the entire coating, promoting bony in-growth and on-growth. Similar surfaces can now be achieved much more readily via 3D Printing.

Acetabular cups, which are part of total hip replacement, showing Himed’s patented porous MATRIX TI® surface coating. Similar surfaces can now be achieved more readily via 3D Printing (Photo Credit: Craig Rosenblum)

Jenny: What inspired you to start your journey?

Craig: I studied Materials Science & Engineering to satisfy my curiosity about the relationship between the structures and properties of materials. Materials are all around us, and a deeper understanding of this correlation allows for the most complex engineering questions to be answered. It also inspires new and improved materials to be created, including via 3D printing technology. Biomaterials, specifically materials used to mimic hard tissue like bone and tooth enamel, have always been of primary interest to me.

Rosenblum’s research at Johns Hopkins University explored the intratooth, intertooth, and interspecies variations across dental enamel. (Photo Credit: Craig Rosenblum)

Jenny: Who inspired you the most along this journey in 3D printing?

Craig: It’s difficult to single one individual or experience. I think anytime you are at the cutting edge of research in such a fast-developing field as 3D printing, collaborations of any extent can be valuable and inspirational.

Jenny: What motivates you the most for your work? 

Craig: The desire to be innovative, try new ideas, think outside of the box, and learn from the results. Many biomaterials may appear relatively small, but knowing that a high-quality product can make a big difference for a patient in need should be a motivator for anyone in this field.

Download Himed post-processing white paper (Photo Credit: Craig Rosenblum)

Jenny: What is/are the biggest obstacle(s) in your line of work? If you have conquered them, what were your solutions? 

Craig: At Himed, many of the processes and solutions we now offer routinely were inspired by specific client requests. Our philosophy is for a customized approach based on the specific engineering challenge at hand. While we operate in a small niche industry, being able to establish these conversations and introduce our technologies to key opinion leaders can often represent the biggest challenge. This is how our global company has succeeded for three decades. While there is no substitute for face-to-face encounters, a positive takeaway from the pandemic is that we are all now more well-versed in forming connections in many more unique ways.

As I’ll discuss on October 6, MCD Apatitic Abrasive was originally developed as a biocompatible and resorbable grit-blast media used to increase the surface area that comes in direct contact with the bone or as a surface preparation prior to the application of a subsequent coating. However, collaborations with other device manufacturers around the globe have inspired more unique applications for MATRIX MCD® than originally intended, including for the post-processing of additively manufactured titanium implantable devices. This post-processing offers critical improvements to remove surface imperfections, including visible layer lines, loosely adherent residual beads, irregularities on the build surface, and other surface defects.

SEM image of Himed’s proprietary MCD Apatitic Abrasive. Formulated to be as hard as possible (approximately 500 HV100), this bioresorbable abrasive has proven effective in post-processing additively manufactured titanium implantable devices. (Photo Credit: Craig Rosenblum)

Jenny: What do you think is (are) the biggest challenge(s) in 3D Printing/bio-printing? What do you think the potential solution(s) is (are)?

Craig: As if there weren’t enough challenges associated with the design and regulatory approval of traditional stock 3D printed surgical implants, patient-specific 3D printed implants present even more obstacles. Patient-specific implants are precisely additively manufactured or customized, to match a patient’s specific anatomy and have the potential to revolutionize the industry.

Coming from a manufacturing background, I have many supply chain concerns about how such a model is achievable. There is no current FDA standard to abide by, simply a risk-based guidance approach. Perhaps most importantly, I wonder how receptive surgeons and patients will be to trying these new technologies with limited long-term data. 

I think the solution starts with educating the surgeons, and hopefully, artificial intelligence is transformative. Everything in medicine takes longer than we think it’s going to take, further delaying this potential revolution.

Post-processing manufacturing (Photo Credit: Craig Rosenblum)

Jenny: If you are granted three wishes by a higher being, what would they be? 


  1. Past – To reflect and learn from past experiences, but live life without any regrets
  2. Present – The mindfulness to appreciate the present moment rather than a natural instinct to immediately think “what’s next?”
  3. Future – The ability to look into and learn from the future in advance

Jenny: What advice would you give to a smart driven college student in the “real world”? What bad advice you heard should they ignore? 

Craig: Follow your passion and don’t give up. Trust your instinct. Set high standards and hold yourself accountable. Seek opportunities to connect with and learn from others. Don’t put off until tomorrow what you can do today.

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