A Polymeric Piezoelectric Tactile Sensor Fabricated by 3D Printing and Laser Micromachining for Hardness Differentiation during Palpation

• Published in: Micromachines (Basel) Vol. 13; no. 12; p. 2164
• Main Authors: Ge, Chang, Cretu, Edmond
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.12.2022; MDPI
• Subjects: 3-D printers; 3D printing; bionic MEMS; Bionics; Comparative analysis; Design; Diagnostic tests; Differentiation; Directional sensitivity; elastomer 3D printing; Hardness; Integrated circuit fabrication; Laparoscopy; Laser machining; laser micromachining; Lasers; Low cost; Manufacturing; Mechanical properties; Microelectromechanical systems; Micromachining; Object recognition; palpation; piezoelectric tactile sensor; Piezoelectricity; Polymer films; Polymers; Rapid prototyping; Screen printing; Sensors; Soft tissues; Tactile sensors (robotics); Thin films; Three dimensional printing; tissue hardness differentiation; bionic MEMS; laser micromachining; piezoelectric tactile sensor; elastomer 3D printing; tissue hardness differentiation; palpation
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi13122164

Tactile sensors are important bionic microelectromechanical systems that are used to implement an artificial sense of touch for medical electronics. Compared with the natural sense of touch, this artificial sense of touch provides more quantitative information, augmenting the objective aspects of several medical operations, such as palpation-based diagnosis. Tactile sensors can be effectively used for hardness differentiation during the palpation process. Since palpation requires direct physical contact with patients, medical safety concerns are alleviated if the sensors used can be made disposable. In this respect, the low-cost, rapid fabrication of tactile sensors based on polymers is a possible alternative. The present work uses the 3D printing of elastic resins and the laser micromachining of piezoelectric polymeric films to make a low-cost tactile sensor for hardness differentiation through palpation. The fabricated tactile sensor has a sensitivity of 1.52 V/mm to mechanical deformation at the vertical direction, a sensitivity of 11.72 mV/HA in sensing material hardness with a pressing depth of 500 µm for palpation, and a validated capability to detect rigid objects buried in a soft tissue phantom. Its performance is comparable with existing piezoelectric tactile sensors for similar applications. In addition, the tactile sensor has the additional advantage of providing a simpler microfabrication process.