RTP Company Develops Material Solutions for Surgical Robotic Systems

RTP Company, a global compounder of custom engineered thermoplastics, has developed a selection of thermoplastic compounds that provide strength, durability, color, flame retardance, wear and chemical resistance, and more for surgical robotic systems. 
 
“Surgical robots are becoming more prevalent because they are minimally invasive and precisely accurate, which helps the patient recover more quickly,” explained Bob Williams, global healthcare manager at RTP Company. “RTP Company engineers have been assisting the medical industry with material solutions for over 35 years. We are passionate about helping robotic designers find the right materials for surgical robotic systems and components.” 
 
RTP Company offers thermoplastic technologies that can be utilized for surgical robotic systems, with special properties such as strength, flame retardance, wear/chemical/impact resistance, color, and the ability to withstand sterilization methods. If required, biocompatibility support can be provided for many of these compounds. These materials are used for robotic systems and housings; monitor components like housings, bezels, bases, and tool holders; reusable instruments such as cannulas, trocar housings, grasper tips and endo ports; single-use tools such as surgical forceps, shears, tweezers and tool housings; and medical staplers. 
 
“We specialize in formulating compounds with the appropriate resins and additives to create materials that provide the properties required by robotic systems,” noted Williams. RTP Company compounds for surgical robotic systems and components are available globally  in a variety of resin and additive combinations to fit precise requirements and meet the demands of surgical use.
 
The company also offers tribology data from an innovative new friction test to help designers of drug delivery devices select the best possible material for single-use applications.

Designers, OEMs and molders are keenly aware of the issues that can arise when single-use drug delivery devices fail. It is critical that devices such as auto-injectors, injection pens, stop cocks, and safety syringes move easily and have a low break-away force to overcome friction.  Various external factors, such as long periods of inactivity, shipping, and cold storage conditions can all have an effect on the friction behavior of plastic-on-plastic moving parts. These factors increase the chances of stick-slip phenomena or “stiction,” resulting in poor performance of a drug delivery device.

Until recently, there were no established industry tests that accurately predicted friction behavior in single-use devices, making precise material selection difficult. RTP Company has developed an innovative friction test to accurately predict friction behavior in single-use devices. Using the new test method, RTP Company explored base resins including PC, POM, ABS, PC/ABS, HDPE, and PBT. These resins were tested in a variety of combinations with friction reducing additives including PTFE, PFPE Oil, and a selection of silicones, along with RTP Company’s own All Polymeric Wear Alloy (APWA Plus).

Testing the friction behavior in various combinations of resins and friction reducing additives (known as “friction pairings”) involves the measurement of the Static and the Dynamic Coefficients of Friction. The threshold representing the smallest delta between the two measurements has been coined by RTP Company tribologists as the “Glide FactorSM”. Consistent, repeatable tests showed that the ideal friction pairings exhibited low Static Coefficient of friction (< 0.15) and a Glide FactorSM of < 0.015 (see Figure 1).
 
The data collected from these tests can prove invaluable, eliminating the need for trial and error when choosing the correct low friction thermoplastic. In addition, with proper material selection, single-use devices will perform more consistently without the need for external lubrication and extra processing steps, thereby decreasing manufacturing costs and time-to-market.