5 research outputs found
Flexible-to-Stretchable Mechanical and Electrical Interconnects
Stretchable electronic devices that
maintain electrical
function
when subjected to stress or strain are useful for enabling new applications
for electronics, such as wearable devices, human–machine interfaces,
and components for soft robotics. Powering and communicating with
these devices is a challenge. NFC (near-field communication) coils
solve this challenge but only work efficiently when they are in close
proximity to the device. Alternatively, electrical signals and power
can arrive via physical connections between the stretchable device
and an external source, such as a battery. The ability to create a
robust physical and electrical connection between mechanically disparate
components may enable new types of hybrid devices in which at least
a portion is stretchable or deformable, such as hinges. This paper
presents a simple method to make mechanical and electrical connections
between elastomeric conductors and flexible (or rigid) conductors.
The adhesion at the interface between these disparate materials arises
from surface chemistry that forms strong covalent bonds. The utilization
of liquid metals as the conductor provides stretchable interconnects
between stretchable and non-stretchable electrical traces. The liquid
metal can be printed or injected into vias to create interconnects.
We characterized the mechanical and electrical properties of these
hybrid devices to demonstrate the concept and identify geometric design
criteria to maximize mechanical strength. The work here provides a
simple and general strategy for creating mechanical and electrical
connections that may find use in a variety of stretchable and soft
electronic devices
Flexible-to-Stretchable Mechanical and Electrical Interconnects
Stretchable electronic devices that
maintain electrical
function
when subjected to stress or strain are useful for enabling new applications
for electronics, such as wearable devices, human–machine interfaces,
and components for soft robotics. Powering and communicating with
these devices is a challenge. NFC (near-field communication) coils
solve this challenge but only work efficiently when they are in close
proximity to the device. Alternatively, electrical signals and power
can arrive via physical connections between the stretchable device
and an external source, such as a battery. The ability to create a
robust physical and electrical connection between mechanically disparate
components may enable new types of hybrid devices in which at least
a portion is stretchable or deformable, such as hinges. This paper
presents a simple method to make mechanical and electrical connections
between elastomeric conductors and flexible (or rigid) conductors.
The adhesion at the interface between these disparate materials arises
from surface chemistry that forms strong covalent bonds. The utilization
of liquid metals as the conductor provides stretchable interconnects
between stretchable and non-stretchable electrical traces. The liquid
metal can be printed or injected into vias to create interconnects.
We characterized the mechanical and electrical properties of these
hybrid devices to demonstrate the concept and identify geometric design
criteria to maximize mechanical strength. The work here provides a
simple and general strategy for creating mechanical and electrical
connections that may find use in a variety of stretchable and soft
electronic devices
Flexible-to-Stretchable Mechanical and Electrical Interconnects
Stretchable electronic devices that
maintain electrical
function
when subjected to stress or strain are useful for enabling new applications
for electronics, such as wearable devices, human–machine interfaces,
and components for soft robotics. Powering and communicating with
these devices is a challenge. NFC (near-field communication) coils
solve this challenge but only work efficiently when they are in close
proximity to the device. Alternatively, electrical signals and power
can arrive via physical connections between the stretchable device
and an external source, such as a battery. The ability to create a
robust physical and electrical connection between mechanically disparate
components may enable new types of hybrid devices in which at least
a portion is stretchable or deformable, such as hinges. This paper
presents a simple method to make mechanical and electrical connections
between elastomeric conductors and flexible (or rigid) conductors.
The adhesion at the interface between these disparate materials arises
from surface chemistry that forms strong covalent bonds. The utilization
of liquid metals as the conductor provides stretchable interconnects
between stretchable and non-stretchable electrical traces. The liquid
metal can be printed or injected into vias to create interconnects.
We characterized the mechanical and electrical properties of these
hybrid devices to demonstrate the concept and identify geometric design
criteria to maximize mechanical strength. The work here provides a
simple and general strategy for creating mechanical and electrical
connections that may find use in a variety of stretchable and soft
electronic devices
Flexible-to-Stretchable Mechanical and Electrical Interconnects
Stretchable electronic devices that
maintain electrical
function
when subjected to stress or strain are useful for enabling new applications
for electronics, such as wearable devices, human–machine interfaces,
and components for soft robotics. Powering and communicating with
these devices is a challenge. NFC (near-field communication) coils
solve this challenge but only work efficiently when they are in close
proximity to the device. Alternatively, electrical signals and power
can arrive via physical connections between the stretchable device
and an external source, such as a battery. The ability to create a
robust physical and electrical connection between mechanically disparate
components may enable new types of hybrid devices in which at least
a portion is stretchable or deformable, such as hinges. This paper
presents a simple method to make mechanical and electrical connections
between elastomeric conductors and flexible (or rigid) conductors.
The adhesion at the interface between these disparate materials arises
from surface chemistry that forms strong covalent bonds. The utilization
of liquid metals as the conductor provides stretchable interconnects
between stretchable and non-stretchable electrical traces. The liquid
metal can be printed or injected into vias to create interconnects.
We characterized the mechanical and electrical properties of these
hybrid devices to demonstrate the concept and identify geometric design
criteria to maximize mechanical strength. The work here provides a
simple and general strategy for creating mechanical and electrical
connections that may find use in a variety of stretchable and soft
electronic devices
Silicones for Stretchable and Durable Soft Devices: Beyond Sylgard-184
This paper identifies and characterizes
silicone elastomers that
are well-suited for fabricating highly stretchable and tear-resistant
devices that require interfacial bonding by plasma or UV ozone treatment.
The ability to bond two or more pieces of molded silicone is important
for creating microfluidic channels, chambers for pneumatically driven
soft robotics, and other soft and stretchable devices. Sylgard-184
is a popular silicone, particularly for microfluidic applications.
However, its low elongation at break (∼100% strain) and moderate
tear strength (∼3 N/mm) make it unsuitable for emerging, mechanically
demanding applications of silicone. In contrast, commercial silicones,
such as Dragon Skin, have excellent mechanical properties yet are
difficult to plasma-bond, likely because of the presence of silicone
oils that soften the network yet migrate to the surface and interfere
with plasma bonding. We found that extracting silicone oligomers from
these soft networks allows these materials to bond but only when the
Shore hardness exceeds a value of 15 A. It is also possible to mix
highly stretchable silicones (Dragon Skin and Ecoflex) with Sylgard-184
to create silicones with intermediate mechanical properties; interestingly,
these blends also only bond when the hardness exceeds 15 A. Eight
different Pt-cured silicones were also screened; again, only those
with Shore hardness above 15 A plasma-bond. The most promising silicones
from this study are Sylgard-186 and Elastosil-M4130 and M4630, which
exhibit a large deformation (>200% elongation at break), high tear
strength (>12 N/mm), and strong plasma bonding. To illustrate the
utility of these silicones, we created stretchable electrodes by injecting
a liquid metal into microchannels created using such silicones, which
may find use in soft robotics, electronic skin, and stretchable energy
storage devices