Improved Dual Electrothermal Microgripper based on a Chevron actuator

In  Micro-Electro-Mechanical  Systems  (MEMS)  technology,  there  is  an  important  interest  in  the characterization of devices using dynamic analysis, which is a technique to determine the dynamic behavior of a structure or component, involving time, inertia and the possibly damping of the structure. This  paper  is  focused  on  the  analysis  and  simulation  of  an  improved  dual  microgripper  and  its components:  microcantilever  and  chevron.  In  addition,  a  movement  amplifier  based  on  an arrangement of beams was also designed in order to improve the  opening  of each  jaw of the top gripper. Dual microgrippers are designed on silicon and implemented using Professional Autodesk Inventor. Top gripper is initially closed, while the down one is initially open. The analytical response of the  microgripper  components was acquired with Steady-State Thermal, Static Structural, and Modal modules of Ansys Workbench Software. The  dynamic  behavior,  resonance  frequencies  for  chevron  actuator  and  dual  microgrippers  are presented.  Simulation  results  show  the  modal  shapes  of  allanalyzed  devices,  determining  their respective modal frequencies. A comparison between initial and improved dual  microgrippers was also  performed. About the top grippers, the increment showed by the improved microgripper in total displacement is of 24.4%, and the temperature distribution only showed a little reduction (7%). For the case of the down gripper, the total displacement decrease in approximately 50%, force remains without change and its temperature shows a little decrement (7.2%). In both dual microgrippers, the biggest temperature value resides in the chevron inside, at the top part of its shuttle, with 162.76°C. Supply voltage was considered from 0 to 7 V. This swept could be useful to determine  the  more  appropriate  voltage  level  to  obtain  adesirable  response.  In  each  analyzed device, their corresponding modal shapes, using FEA, were determined. The modal shapes analysis allow to understand the performance of the analyzed devices, at the correspondent frequency. From the comparison between initial and improved dual microgrippers, implemented with Silicon, special attention was given to the top grippers. Total displacement showed by the improved microgripper has a  maximum  value  of  0.86  μm.  Third  natural  frequency  remains  almost  without  change (4.7%), increasing at 70.38 kHz and the temperature distribution only showed a little reduction (7%, maximum temperature was  of 131.49°C), which is better for practical applications. For the case of the down grippers of improved dual microgripper, the total displacement decrease in approximately 50% (with a value of 0.18 μm), force remains without change (3.8 μN) and its temperature decreases (7.2%), at 162.77°C, which is also better for practical applications. These parameters values of the improved dual microgripper are illustrative for possible applications.

Read full article:


Leave a Reply

Your email address will not be published. Required fields are marked *