The rise of 3D printing for micro-medical applications

Micro-3D printing/additive manufacturing (AM) continues to drive and speed up the development of medical devices and microfluidics, as well as medical research. There are currently several very strong trends driving micro-AM adoption for medical uses:

• A rising demand for small components due to more minimally invasive surgeries
• The customization of devices and models specifically to each patient
• A push for miniaturization of medical devices
• Ongoing growth of microfluidics in research

Unlike traditional methods such as micro injection molding or CNC machining, which are costly and limited by tooling requirements, 3D printing allows for intricate geometries without assembly hassles. This capability reduces time and effort, leading to faster development compared to traditional techniques. The application areas where these trends are demonstrated include micro needles, microfluidic chips, and personal medical device miniaturization.

There are various designs of micro needles for different purposes that have been created, some of which are intended for drug delivery, while others are for collecting skin cells. Some of the foremost micro-3D printing systems available on the market allow for the simultaneous production of hundreds of micro needles on a single build plate in a matter of hours, ensuring smooth, high-quality, and sharp precise tips.

When it comes to using micro-3D-printed micro fluidic chips, a recent collaboration between my own company and the Technical University Munich exemplifies the advantages that exist. In this instance, we partnered with the institution to develop a scalable droplet microfluidic workflow for generating patient-derived organoids (PDOs) at the Center for Functional Protein Assemblies (CPA). The challenge involved achieving micron-level accuracy in fabricating channels for proper fluid behaviour without channel occlusion. Traditional methods proved laborious and limited in scalability, prompting the adoption of micro-3D printing technology from our Fabrica product line. The successful fabrication of a functional droplet microfluidic device highlighted the benefits of a monolithic design, simplifying cleaning and sterilization procedures while minimizing inter-experimental variations. This collaboration represents a significant advancement in droplet microfluidics, promising groundbreaking discoveries in protein assemblies and cancer biology, and heralds a new era of efficiency and innovation in biomedical research.

Personal medical device miniaturization

Another trend in healthcare driving the demand for very small parts, particularly micro-AM parts, is the growing use of miniature medical devices, which also links to the increasing acceptance of wearable medical devices. An example of this trend is Torramics, which recently used its Fabrica 3D printing technology to develop a small, disposable, electronic drug delivery device. Called the Torramics nanoPatch, this is based on NASA’s nanoPump technology and offers a convenient, reliable, and cost-effective treatment for chronic conditions such as diabetes. By leveraging micro-AM, Torramics has shortened its development cycle from more than one week to less than 24 hours, at less than 10% of the cost.

Medical research

In addition to research conducted with Microfluidics, intensive medical research also benefits from micro-3D printing technology. A team of researchers from the University of Bordeaux’ IMN: Neurodégénératives Diseases Institute in France, as well as institutions in Canada – namely the CERVO Research Center and the University Laval – have just worked with us to produce a medical device capable of measuring neuronal activity in the spinal cord of a freely moving mouse. Recording the electrical activity of neurons in this area of the mouse’s anatomy was challenging due to movement induced by walking and breathing. To address this, our team deployed our micro-AM technology using cytotoxicity1-cleared Fabrica M810 resin to design a brace attached to the mouse’s vertebra to hold two electrodes in place. The technology enabled the rapid and cost-effective production of the part and met the fundamental design objective for minute holes for the electrodes that measured just 110μm and 2.7mm wide.

Conclusion

As these examples hopefully demonstrate, micro-AM technology is becoming an increasingly recognized and formidable solution for prototyping medical device components and microfluidic chips and for producing large quantities of parts. Further exemplifying its versatility, it can also be deployed to print molds or mold inserts for micro parts, which can then be used with micro-injection molding solutions to create parts from a wider variety of thermoplastics. Micro-AM technology continues to attract manufacturers from a multitude of sectors as a fast and cost-effective technology solution to address their exacting application requirements.

About the author: Nir Sade is GM, AM Division & SVP Product at Nano Dimension, a provider of micro-3D printing/additive manufacturing (AM) solutions for a diverse array of applications spanning industry sectors such as medical, aerospace, automotive, consumer, electronics, optics, and semi-conductors.

¹M810 was tested according to ISO 10993 – part 5: Tests for in vitro cytotoxicity and was found to be non-cytotoxic. EN ISO 10993 defines the series of standards for evaluating the biocompatibility of medical devices.