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
Patterned Liquid Metal Contacts for Printed Carbon Nanotube Transistors
Flexible and stretchable
electronics are poised to enable many
applications that cannot be realized with traditional, rigid devices.
One of the most promising options for low-cost stretchable transistors
are printed carbon nanotubes (CNTs). However, a major limiting factor
in stretchable CNT devices is the lack of a stable and versatile contact
material that forms both the interconnects and contact electrodes.
In this work, we introduce the use of eutectic gallium–indium
(EGaIn) liquid metal for electrical contacts to printed CNT channels.
We analyze thin-film transistors (TFTs) fabricated using two different
liquid metal deposition techniquesî—¸vacuum-filling polydimethylsiloxane
(PDMS) microchannel structures and direct-writing liquid metals on
the CNTs. The highest performing CNT–TFT was realized using
vacuum-filled microchannel deposition with an <i>in situ</i> annealing temperature of 150 °C. This device exhibited an on/off
ratio of more than 10<sup>4</sup> and on-currents as high as 150 ÎĽA/mmî—¸metrics
that are on par with other printed CNT–TFTs. Additionally,
we observed that at room temperature the contact resistances of the
vacuum-filled microchannel structures were 50% lower than those of
the direct-write structures, likely due to the poor adhesion between
the materials observed during the direct-writing process. The insights
gained in this study show that stretchable electronics can be realized
using low-cost and solely solution processing techniques. Furthermore,
we demonstrate methods that can be used to electrically characterize
semiconducting materials as transistors without requiring elevated
temperatures or cleanroom processes