Shock absorbing Metamaterial
What?
As a part of my Micro and Nano additive Manufacturing class, I worked on a project to design a new shock absorbing metamaterial to protect microscale electronics from fall damage. I used Solidworks to design the metamaterial and Ansys Explicit dynamics to evaluate the structure.
How?
To start with the metamaterial, we wanted to come up with our own design with auxetic properties rather than using a pre-existing design. So based on some literature reviews and drawbacks on those design, we came up with this design shown in the image. The dimension of this unit cell of a metamaterial is 50 μm in all the three direction.
Auxetic metamaterial
Though this design can be tricky to manufacture with traditional 3D printing techniques like FDM, using techniques like SLA, we can easily manufacture this structure and with the actual dimension. After designing our unit cell, we conducted Ansys explicit dynamics analysis to investigate it performance and compare it with a chiral metamaterial, a structure known for its shock absorbing properties but are generally flimsy. As a control, we also have a base plate directly drop on to the surface to get the basal stress values.
Ansys Explicit dynamics simulation of my design
Ansys Explicit dynamics simulation of the chiral metamaterial
We got the time vs stress for all these simulations and did a linear fit to those results using origin pro.
Results
Time vs Stress comparing my design (Meta) vs Chiral structure vs control
A close up of the same Time vs Stress linear fit
From the above graphs and stress data we can see that our unit cell design outperformed the chiral metamaterial by 12% and a three-layer structure of our metamaterial outperformed the chiral structure by nearly 30%. Note that these stress were observed on a plate placed above the metamaterial structure.