Impact-Based Amplification and Frequency Down-Conversion of Piezoelectric Actuation for Small Robotics

Abstract

This paper explores a concept for dynamic amplification of piezoelectric actuator motion using repeated impacts between the active transducer and a compliant amplification mechanism. The design shows good performance in amplifying vibration of a lead–zirconate–titanate (PZT) bimorph while down-converting the output frequency of motion from more than 150 Hz to less than 20 Hz. A simple dynamic model is used to identify the conceptual opportunities for impact-based amplification of PZT displacement. Experimental results are gathered from a prototype system with dimensions 55 mm × 22 mm × 1 mm. PZT displacement is amplified by a factor of more than 100 with near-periodic output oscillations at select input frequencies. Implications for leveraging the low-frequency output oscillations in small mobile robots are briefly discussed.

Developments and Challenges of Miniature Piezoelectric Robots: A Review

“…As shown in Figure 12 a , the piezoelectric ceramics that are applied in MPRs can be divided into the rigid ones and the soft ones, the former is usually prepared by two methods of traditional processing and AM, while the later mainly includes the PVDF (polyvinylidene difluoride) and MFC (macrofiber composite) materials. [ 246 , 247 , 248 , 249 , 250 ] The rigid piezoelectric ceramics are usually made of PZT (lead zirconate titanate, an inorganic compound with the chemical formula Pb[Zr x Ti 1 − x ]O 3( 0 ≤ x ≤1)), which has great sensitivity and high operating temperature [ 251 , 252 , 253 ] The main steps of the traditional machining method to fabricate the PZT ceramics are shown in i) of Figure 12b , the PZT powders are made into PZT ceramics; then, the PZT ceramics are cut into the required shapes to manufacture the piezoelectric actuating elements. [ 254 , 255 ] This machining method for PZT ceramic is very mature, and most of MPRs utilize the rigid PZT ceramics fabricated by the traditional machining method.…”

“…As shown in Figure 12a, the piezoelectric ceramics that are applied in MPRs can be divided into the rigid ones and the soft ones, the former is usually prepared by two methods of traditional processing and AM, while the later mainly includes the PVDF (polyvinylidene difluoride) and MFC (macrofiber composite) materials. [246][247][248][249][250] The rigid piezoelectric ceramics are usually The common process and examples of AM method applied to MPRs: i) the usual main five steps in the 3D printing process; ii-iv) three hexapod MPR that using AM method to fabricate their robot bases. Reproduced with permission.…”

Theoretical investigation of bistable piezoelectric energy harvester using frequency down-conversion

“…48 A compliant amplification mechanism to achieve dynamic amplification of piezoelectric actuator motion with frequency down-converting from 150 Hz to 20 Hz. 49 An architecture for a fully functional, space-compliant SCORE-SAR receiver module is presented in which a PIC powered by a laser and a local electrical oscillator (LO) operates the down-conversion to intermediate frequency. 50 Moreover, a frequency down-converter in the ranges of IR and THz frequencies was found to be promising with 75% amplification efficiency and 25% maximal frequency conversion.…”