by Jackie Johnson Jackie Johnson No Comments

The Different Types of 3D Printing

3D printing has seemingly taken over the world! Because of it’s increasing popularity with both manufacturers and hobbyists, more and more 3D printers are being produced each year. There also many different types of 3D printing technologies, which vary in cost, effectiveness, materials used, speed and cost. These include:

  • Stereolithography (SLA)
  • Selective Laser Sintering (SLS)
  • Fused Deposition Modeling (FDM)
  • Digital Light Process (DLP)
  • Multi Jet Fusion (MJF)
  • Direct Metal Laser Sintering (DMLS)
  • Electron Beam Melting (EBM)

Because there are quite a few, we will be breaking this post into two parts, with the next part coming next week, so stay tuned! 

In the meantime, let’s discuss some 3D printing methods!

FDM Printing

FDM Printing

FDM

Fused Deposition Modeling (FDM) is one of the most widely available 3D Printing technology today. It uses a process called material extrusion, where a solid material, usually some form of thermoplastic (PLA, ABS, PET, etc.) is pushed through a heated nozzle attached to the printer head, melting the material. As the printer head moves along specific coordinates, it deposits the material, where it cools and solidifies, forming a solid object. 

  • Relatively Inexpensive
  • Ease of Use
  • Wide Variety of Materials

SLA

Stereolithography (SLA) uses a printing method called vat polymerization, where a material called photopolymer resin is exposed to an ultraviolet laser, which is used to draw pre-preprogrammed designs or shapes onto the material. This process is repeated for each layer until a 3D object is completed, and then washed in a solvent to remove excess resin. Because of this, SLA printing is often messy. You are also restricted to printing with resin materials, which can be expensive. The benefits, however, include:

  • Higher quality prints than FDM
  • Faster Print Speed
  • Stronger Finished Products

SLA Printer

SLS

Selective laser sintering (SLS) uses a laser to sinter powdered material together until a 3D model is formed. Unlike FDM and SLA, which have become incredibly popular in the hobbyist market, SLS has remained mostly in the realm of industrial manufacturing, because of the high cost (and potential dangers) of the lasers and materials. There are many advantages to SLS printing, including: 

  • The ability to print objects without support structures. 
  • High Strength and Stiffness
  • Good Chemical Resistance
  • Incredibly fast print speed

Stay tuned for next week for part two, where we discuss even more 3D printing methods!

Medical ventilator
by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

How Canted Coils Springs are Used in Medical Applications

Canted Coil Springs

There are several distinct benefits to be had from using canted coil springs in place of more traditional springs. Because of this, it should come as no surprise that these springs are used extensively in medical applications. 

Canted Coil Springs Are Effective Electrical Connectors and Contacts

Canted coil springs are being used more and more for electrical contacts and connectors. Canted coil connectors make it easier to replace leads and lead segments without harming the patient, and lead interface solutions based on canted coil springs can significantly reduce risk to the patient. In some applications, the procedure time and the patient’s recovery time can be reduced through the wise application of canted coil springs. Canted coil springs also provide high contact power density with a minimal amount of temperature rise. In many instances, they can also reduce the size of the medical device and provide multi-channel connections.

Canted Coil Springs Can Provide EMI and RF Shielding

Another benefit of canted coil springs is their ability to provide shielding from harmful EMI and RFI interference in applications such as ultrasound equipment and vital signs monitors. Many times the medical data being transmitted cannot afford a compromise in its integrity of the disruption of the data flow. Canted coil springs can actually be tuned to meet specific impedance specifications so that medical equipment and devices can be protected from dangerous crosstalk interference.

Canted Coil Springs Can Be Used in Spring-Energized Seals

Canted coil springs can be used in spring-energized seals in medical equipment and external devices as well as implantable devices. Spring-energized seals are often used to maintain a seal when there are problems with hardware gaps, runout, eccentric contact surfaces, and vacuum pressures. In short, spring-energized seals can provide an effective seal where other seals would fail, and when canted coil springs are used then a far more consistent spring force can be applied. 

Canted Coil Springs Serve as Reliable Mechanical Connectors

 

Canted coil springs can provide a reliable connector in three specific ways: 

  • Holding and retaining two parts in alignment with customized forces, often used for surgical instrumentation
  • Securely fastening two parts together while allowing them to still be unlatched (where the latching force can be customized), which is also being used with surgical instrumentation
  • Permanently locking two parts together, including use during orthopedic implant surgery

Unlike most mechanical connector solutions, canted coil springs can achieve these connections with strength, reliability, and incredibly high precision. In addition, when canted coil springs are used as mechanical connectors, there is an option to customize the forces for insertion and breakaway. 

Medical ventilator

Medical Applications of Canted Coil Springs

There are a host of specific medical applications where canted coil springs have proven invaluable. The following is just a sampling:

  • Cochlear implants
  • Implantable medication pumps
  • Insulin delivery systems
  • Orthopedic instruments
  • High-speed surgical power tools
  • Neurostimulators
  • Ultrasound equipment
  • Pain management devices
  • Vital signs monitors
  • Hemodialysis equipment
  • Defibrillators
  • Cardiac rhythm management devices

Conclusion

Canted coil springs are used in connection with everything from neurostimulators to orthopedic implant surgery. Their ability to serve as electrical connectors/contacts, shield from EMI and RF interferences, serve as the energizer in spring-energized seals, and provide tailored mechanical connections make them ideal solutions for many different medical devices and implantables.