Integrated electronic device with flexible and stretchable substrate
A flexible and stretchable integrated electronic device comprising a substrate having a stiffness gradient, wherein a rigid electronic device is embedded within the substrate. The stiffness gradient within the substrate prevents delamination at the interface between the substrate and the embedded device. A method of fabricating an integrated electronic device having a stiffness gradient comprises applying a curing agent to an uncured polymer base material.
1. A method of making an integrated electronic device having a stiffness gradient, the method comprising:
embedding a rigid electronic device in a substrate comprising an uncured polymer base, and
applying a curing agent to the substrate in a pattern,
wherein applying the curing agent in the pattern creates a portion of the substrate adjacent the embedded electronic device with a modulus in between a modulus of a portion of the substrate not adjacent to the embedded electronic device and the modulus of the rigid electronic device.
2. The method of claim 1 , wherein the curing agent is applied to a surface of the substrate using an inkjet device, an aerosol jetting device, or a 3D printer.
3. The method of claim 2 , further comprising:
thinning the curing agent using a solvent.
4. The method of claim 3 , wherein the solvent is selected from the group consisting of xylene, trichlorobenzene, hexane, and isopropyl alcohol.
5. The method of claim 1 :
wherein the substrate comprises polydimethylsiloxane;
wherein applying the curing agent to the substrate in the pattern comprises:
applying the curing agent to a first section adjacent to the rigid electronic device at a ratio of base-to-curing agent of 5:1; and
applying the curing agent to a second section not adjacent to the rigid electronic device at a ratio of base-to-curing agent of 20:1.
6. The method of claim 1 , wherein the pattern comprises:
a first area of the substrate adjacent to the rigid electronic device and a second area not adjacent to the rigid electronic device,
wherein the first area receives a greater amount of the curing agent.
7. The method of claim 1 , wherein the pattern comprises a continuous gradient.
8. The method of claim 1 , wherein applying the curing agent to the substrate comprises:
applying the curing agent to a surface of the substrate; and
allowing the curing agent to diffuse into the substrate.
9. The method of claim 1 , wherein the curing agent is applied manually.
10. The method of claim 2 , wherein the substrate is heated as the curing agent is applied to the substrate.
11. The method of claim 2 , wherein the inkjet device, aerosol jetting device, or 3D printer applies the curing agent in the pattern comprising a plurality of overlapping areas of increasing size, each of the plurality of overlapping areas located in part over the rigid electronic device, thereby creating a gradient in the amount of the curing agent applied to the substrate.
12. The method of claim 2 , further comprising:
controlling diffusion of the curing agent by adjusting at least one of: a temperature of the substrate, a viscosity of the curing agent, and a surface tension of the curing agent.
13. The method of claim 2 , wherein the pattern replicates a wiring pattern of the electronic device.
14. The method of claim 1 , wherein applying the curing agent to the substrate in the pattern comprises:
applying the curing agent to a first section adjacent to the rigid electronic device to create a first base-to-curing agent ratio;
applying the curing agent to a second section not adjacent to the rigid electronic device at a second base-to-curing agent ratio;
wherein the first ratio is less than the second ratio.