Force Sensing Surgical Forceps Using Novel Piezoelectric TFT Array for Robotic Surgery

Minimally invasive robotic surgery offers many advantages over conventional surgery because it can reduce risks including smaller incisions, faster recovery, less trauma to the patient, and the potential to be conducted from a distance. To exploit these advantages, surgical robots must be equipped with tactile feedback in the surgical site, thereby equipping them with the sense of touch.

Tactile feedback is critically important for surgeons to characterize and manipulate various types of healthy tissue with different mechanical properties, manipulate tumors, and suture incisions with arbitrary geometries leading to improved patient outcomes. To bring the capabilities of tactile sensation to minimally invasive robotic surgery, multiple sensors should be placed at the surgical forceps, such that the interaction between the tissue and the forceps can be recorded and delivered to surgeons via haptic and/or visual interfaces.

However, deploying sensors at the surgical forceps is very challenging due to their extremely limited space. In this project, we will directly integrate high-resolution force sensor arrays with tips of the surgical forceps and demonstrate their integration with the da Vinci surgical robot to provide high spatiotemporal tactile sensation for haptic feedback to the operating surgeon.

The project provides training opportunities for undergraduate, high school, and under-represented minority students in interdisciplinary research in materials science, engineering, and medicine. It augments and improves the course curriculum and fosters a robust translational exchange with clinical partners.

To integrate novel microforce sensor arrays with surgical forceps to give surgeons the sense of touch, we will develop piezoelectric zinc oxide (ZnO) thin film transistors (TFTs) on flexible substrates that can simultaneously sense and amplify normal forces. By integrating three-dimensional silicone pillars on top of groups of four ZnO TFTs, we will be able to measure the amplitude and direction of shear forces that are mechanically transduced from the silicone pillars to the ZnO TFTs that produce an amplified electrical signal in response.

The proposed technology can scale sensors down to sub millimeter scales with thin and flexible form factor. By mounting sensors on the jaws of the robotic surgical forceps, we will demonstrate real-time monitoring of normal and shear force applied to the forceps during their interaction with tissue. The monitored force information will be linked with a feedback apparatus to a haptic glove.

Visual feedback will also be provided on the operator display to indicate the amplitude of the force that the forceps exert on the tissue. The effectiveness of the proposed technology will be evaluated by multiple surgeons to derive the advantages in a statistical way. The advances proposed in this research are envisioned to greatly benefit patient care and to further the understanding of the mechanical aspects of the interaction between forceps with tissues, an important step towards developing fully autonomous robotic surgery in the near future.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.