A Novel Two-Stage Constant Force Compliant Microgripper

Abstract

The manipulating objects of the micron scale are easily damaged, hence the microgrippers, the key components in micro manipulating systems, demand precise force control, plus miniaturized size. In consequence, the constant force microgrippers arise at the historic moment, generally lacking the ability to fit different sizes, however. To avoid the overload damage, apply to multi-size microparts and simplify the control method, a novel two-stage compliant constant force microgripper is proposed in this paper. Based on the negative stiffness effect, this gripper is connected in parallel with a two-stage negative stiffness module and a positive stiffness module. Then, the elliptic integral method and the pseudorigid-body method are both employed to derive the kinetostatic and dynamic performances. Finally, the analytical results are validated. It is observed that two-stage constant forces of 1.33 N in 305.6 µm and 1.11 N in 330.8 µm are acquired.

Complaint constant force mechanism using variable stiffness leaf-spring-like beam: Design and experiment

“…To overcome the above weakness, researchers adopt a combination of thin beams with negative stiffness and thin beams with conventional positive stiffness to achieve the constant force output. Such as, the constant force mechanism gripper designed by Hao [4], and the two-stage constant force compatible microgripper designed by Ye [14]. This construction is flexible and operates by the deformation of its material.…”

Design and Testing of a Novel Nested, Compliant, Constant-Force Mechanism with Millimeter-Scale Strokes

“…Zhang et al [ 25 ] designed a novel CFM-based compliant parallel gripper, which achieved constant-force gripping through the combination of a bi-stable beam and a flexible folding beam and had both active and passive constant-force characteristics in the X and Y directions. Ye et al [ 26 ] designed a two-stage flexible, constant-force micro-gripper to achieve constant-force output through a combination of bi-stable and straight beams. Wang et al [ 27 ] used a combination of positive and negative stiffness mechanisms to design a CFM-type precision positioning stage using a piezoelectric ceramic through a displacement amplifier, which could output a constant force for application in biological cell manipulation.…”

Configuration design and experimental verification of a variable constant-force compliant mechanism

“…Different with aforementioned two methods, stiffness-combination CFM obtains constant force by combination of PSS and negative-stiffness structure (NSS) [17]. Ye et al proposed a type of multistage CFM based on the parallel connection of negative and positive stiffness modules [18]. Liu et al designed a compliant constant force gripper by using the combination of positive stiffness and negative stiffness mechanism [19].…”