UCLA researchers in the Department of Bioengineering have developed a novel 3D printing method that produces customizable normal force sensors for robotic surgical applications at high speed and low cost.
Tactile normal force sensors are essential in haptic feedback systems to reduce excessive grip force during robotic surgical operations. Commercially available piezoresistive force sensors used to reduce this excessive grip are expensive and cannot be readily used in biomedical applications and highly customized devices. Manufacturing robotic surgical force sensors with 3D printing can provide a streamlined, inexpensive alternative.
A novel 3D printing method was developed to design and produce normal force sensors for robotic surgical applications. The specific designs can be customized in computer-aided drafting (CAD) software and read by the 3D printer. Conductive graphene filament and copper tapes are used to 3D print the designed force sensor, which can be fitted onto ProGrasp forceps and go through the trocar. As the copper elements are brought closer together, the resistance between the probing points decreases, and the magnitude of force being applied can be determined. Test results have shown effective detection of normal force with good resolution. Moreover, the sensors are expected to have a production cost of approximately 35 cents, which is significantly cheaper than an industry-manufactured normal force sensor. Along with the low cost, the designability of the sensor allows for various applications, even outside of the medical field.
This invention has been tested conducting peg transfers using the Da Vinci Si Surgical System.
3D printing, Normal force sensor, Conductive Graphene filament, Copper, Robotic surgery tools