9 research outputs found
3D Printing of Liquid Metal Embedded Elastomers for Soft Thermal and Electrical Materials
Liquid metal embedded elastomers (LMEEs) are composed
of a soft
polymer matrix embedded with droplets of metal alloys that are liquid
at room temperature. These soft matter composites exhibit exceptional
combinations of elastic, electrical, and thermal properties that make
them uniquely suited for applications in flexible electronics, soft
robotics, and thermal management. However, the fabrication of LMEE
structures has primarily relied on rudimentary techniques that limit
patterning to simple planar geometries. Here, we introduce an approach
for direct ink write (DIW) printing of a printable LMEE ink to create
three-dimensional shapes with various designs. We use eutectic gallium–indium
(EGaIn) as the liquid metal, which reacts with oxygen to form an electrically
insulating oxide skin that acts as a surfactant and stabilizes the
droplets for 3D printing. To rupture the oxide skin and achieve electrical
conductivity, we encase the LMEE in a viscoelastic polymer and apply
acoustic shock. For printed composites with a 80% LM volume fraction,
this activation method allows for a volumetric electrical conductivity
of 5 × 104 S cm–1 (80% LM volume)significantly
higher than what had been previously reported with mechanically sintered
EGaIn–silicone composites. Moreover, we demonstrate the ability
to print 3D LMEE interfaces that provide enhanced charge transfer
for a triboelectric nanogenerator (TENG) and improved thermal conductivity
within a thermoelectric device (TED). The 3D printed LMEE can be integrated
with a highly soft TED that is wearable and capable of providing cooling/heating
to the skin through electrical stimulation
3D Printing of Liquid Metal Embedded Elastomers for Soft Thermal and Electrical Materials
Liquid metal embedded elastomers (LMEEs) are composed
of a soft
polymer matrix embedded with droplets of metal alloys that are liquid
at room temperature. These soft matter composites exhibit exceptional
combinations of elastic, electrical, and thermal properties that make
them uniquely suited for applications in flexible electronics, soft
robotics, and thermal management. However, the fabrication of LMEE
structures has primarily relied on rudimentary techniques that limit
patterning to simple planar geometries. Here, we introduce an approach
for direct ink write (DIW) printing of a printable LMEE ink to create
three-dimensional shapes with various designs. We use eutectic gallium–indium
(EGaIn) as the liquid metal, which reacts with oxygen to form an electrically
insulating oxide skin that acts as a surfactant and stabilizes the
droplets for 3D printing. To rupture the oxide skin and achieve electrical
conductivity, we encase the LMEE in a viscoelastic polymer and apply
acoustic shock. For printed composites with a 80% LM volume fraction,
this activation method allows for a volumetric electrical conductivity
of 5 × 104 S cm–1 (80% LM volume)significantly
higher than what had been previously reported with mechanically sintered
EGaIn–silicone composites. Moreover, we demonstrate the ability
to print 3D LMEE interfaces that provide enhanced charge transfer
for a triboelectric nanogenerator (TENG) and improved thermal conductivity
within a thermoelectric device (TED). The 3D printed LMEE can be integrated
with a highly soft TED that is wearable and capable of providing cooling/heating
to the skin through electrical stimulation
3D Printing of Liquid Metal Embedded Elastomers for Soft Thermal and Electrical Materials
Liquid metal embedded elastomers (LMEEs) are composed
of a soft
polymer matrix embedded with droplets of metal alloys that are liquid
at room temperature. These soft matter composites exhibit exceptional
combinations of elastic, electrical, and thermal properties that make
them uniquely suited for applications in flexible electronics, soft
robotics, and thermal management. However, the fabrication of LMEE
structures has primarily relied on rudimentary techniques that limit
patterning to simple planar geometries. Here, we introduce an approach
for direct ink write (DIW) printing of a printable LMEE ink to create
three-dimensional shapes with various designs. We use eutectic gallium–indium
(EGaIn) as the liquid metal, which reacts with oxygen to form an electrically
insulating oxide skin that acts as a surfactant and stabilizes the
droplets for 3D printing. To rupture the oxide skin and achieve electrical
conductivity, we encase the LMEE in a viscoelastic polymer and apply
acoustic shock. For printed composites with a 80% LM volume fraction,
this activation method allows for a volumetric electrical conductivity
of 5 × 104 S cm–1 (80% LM volume)significantly
higher than what had been previously reported with mechanically sintered
EGaIn–silicone composites. Moreover, we demonstrate the ability
to print 3D LMEE interfaces that provide enhanced charge transfer
for a triboelectric nanogenerator (TENG) and improved thermal conductivity
within a thermoelectric device (TED). The 3D printed LMEE can be integrated
with a highly soft TED that is wearable and capable of providing cooling/heating
to the skin through electrical stimulation
3D Printing of Liquid Metal Embedded Elastomers for Soft Thermal and Electrical Materials
Liquid metal embedded elastomers (LMEEs) are composed
of a soft
polymer matrix embedded with droplets of metal alloys that are liquid
at room temperature. These soft matter composites exhibit exceptional
combinations of elastic, electrical, and thermal properties that make
them uniquely suited for applications in flexible electronics, soft
robotics, and thermal management. However, the fabrication of LMEE
structures has primarily relied on rudimentary techniques that limit
patterning to simple planar geometries. Here, we introduce an approach
for direct ink write (DIW) printing of a printable LMEE ink to create
three-dimensional shapes with various designs. We use eutectic gallium–indium
(EGaIn) as the liquid metal, which reacts with oxygen to form an electrically
insulating oxide skin that acts as a surfactant and stabilizes the
droplets for 3D printing. To rupture the oxide skin and achieve electrical
conductivity, we encase the LMEE in a viscoelastic polymer and apply
acoustic shock. For printed composites with a 80% LM volume fraction,
this activation method allows for a volumetric electrical conductivity
of 5 × 104 S cm–1 (80% LM volume)significantly
higher than what had been previously reported with mechanically sintered
EGaIn–silicone composites. Moreover, we demonstrate the ability
to print 3D LMEE interfaces that provide enhanced charge transfer
for a triboelectric nanogenerator (TENG) and improved thermal conductivity
within a thermoelectric device (TED). The 3D printed LMEE can be integrated
with a highly soft TED that is wearable and capable of providing cooling/heating
to the skin through electrical stimulation
3D Printing of Liquid Metal Embedded Elastomers for Soft Thermal and Electrical Materials
Liquid metal embedded elastomers (LMEEs) are composed
of a soft
polymer matrix embedded with droplets of metal alloys that are liquid
at room temperature. These soft matter composites exhibit exceptional
combinations of elastic, electrical, and thermal properties that make
them uniquely suited for applications in flexible electronics, soft
robotics, and thermal management. However, the fabrication of LMEE
structures has primarily relied on rudimentary techniques that limit
patterning to simple planar geometries. Here, we introduce an approach
for direct ink write (DIW) printing of a printable LMEE ink to create
three-dimensional shapes with various designs. We use eutectic gallium–indium
(EGaIn) as the liquid metal, which reacts with oxygen to form an electrically
insulating oxide skin that acts as a surfactant and stabilizes the
droplets for 3D printing. To rupture the oxide skin and achieve electrical
conductivity, we encase the LMEE in a viscoelastic polymer and apply
acoustic shock. For printed composites with a 80% LM volume fraction,
this activation method allows for a volumetric electrical conductivity
of 5 × 104 S cm–1 (80% LM volume)significantly
higher than what had been previously reported with mechanically sintered
EGaIn–silicone composites. Moreover, we demonstrate the ability
to print 3D LMEE interfaces that provide enhanced charge transfer
for a triboelectric nanogenerator (TENG) and improved thermal conductivity
within a thermoelectric device (TED). The 3D printed LMEE can be integrated
with a highly soft TED that is wearable and capable of providing cooling/heating
to the skin through electrical stimulation
Energy Harvesters for Wearable Electronics and Biomedical Devices
Energy harvesters (EHs) are widely used to transform ambient energy sources into electrical energy, and have tremendous potential to power wearables electronics and biomedical devices by eliminating, or at least increasing, the battery life. Nevertheless, the use of EHs for a specific application depends on various aspects including the form of energy source, the structural configuration of the device, and the properties of materials. This paper presents a comprehensive review of the classification of EHs, notably thermoelectric generators (TEGs), triboelectric nanogenerators (TENGs), and piezoelectric generators (PEGs) that allows a wide variety of devices to be operated. The EHs are discussed in terms of their operating principles, optimization factors, state-of-the-art materials, and device structure, that directly influence their operational efficiency. Besides, the breakthrough performance of each of the EHs listed above is highlighted. From the review and analysis, the maximum output power density of 9.2 mW cm-2, 50 mW cm-2, and 64.9 µW cm-2, respectively, are obtained from the TEG, TENG, and PEG, respectively. Furthermore, recent applications relevant to a specific EH and their output performance, are also enlightened. Eventually, the essential outcomes and future direction from this review are discussed and encapsulated