Microfluidic Patterning of Metal Structures for Flexible Conductors by In Situ Polymer‐Assisted Electroless Deposition

Liang, Suqing; Li, Yaoyao; Zhou, Tingjiao; Yang, Jinbin; Zhou, Xiaohu; Zhu, Taipeng; Huang, Junqiao; Zhu, Julie; Zhu, Deyong; Liu, Yizhen; He, Chuanxin; Zhang, Junmin; Zhou, Xuechang

doi:10.1002/advs.201600313

Cited by 41 publications

(34 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the metal deposition of PAMD is performed in a reductive aqueous environment, the oxidation of the metal is minimized. Metals difficult to fabricate with “metal ink” method such as Cu and Ni can be readily fabricated with an excellent conductivity (e.g., >2.0 × 10 7 S m −1 for Cu and >1 × 10 7 S m −1 for Ni). Importantly, the strong affinity of the polymer chains to both the substrates and the activator moieties ensures excellent adhesion of the final metal layers.…”

Section: Working Principle Of Pamdmentioning

confidence: 99%

Polymer‐Assisted Metal Deposition (PAMD) for Flexible and Wearable Electronics: Principle, Materials, Printing, and Devices

2019

View full text Add to dashboard Cite

such as conducting polymers and carbon nanotubes, metal-the most conventional conductor-still outperforms significantly in terms of the electrical conductivity, device compatibility, materials stability, and cost-effectiveness. [1,[30][31][32][33][34][35][36][37][38] In particular, with the recent understanding of the nanomechanics of the metal and the soft structural design, metal conductors are indispensable for most of the flexible and wearable applications.In the literature, the fabrication of metal conductors typically consists of vacuum deposition of the metal and subsequent patterning with photolithography. Although this fabrication strategy can be directly applied on flexible polymeric substrates, it is often too costly for most flexible applications and may encounter materials instability issues of the flexible substrates at high vacuum or strong solvent. In addition, vacuum technology is not suitable for coating substrates with 3D structures such as foams, fibers, and arbitrary surfaces. This has led to extensive research on developing solution-based metal deposition and printing methods in the past three decades. The most reported solution-based strategy is the so-called "metal ink" method, in which solution-dispersed nanostructured metal particles (including nanoparticles (NPs), nanowires, nanotubes, and nanoplates) or metal precursors are cast or printed onto the flexible substrates and then thermally sintered or chemically reduced to yield the metallic conductors. [39][40][41][42][43] Nevertheless, they are still not widely used because of the following reasons. 1) The metal conductor fabricated through the "metal ink" method shows much lower electrical conductivity compared to their bulk, due to the additives of the ink (such as surfactants, binders, and stabilizers) and the large contact resistance between the NPs. [44,45] 2) The "metal ink" method works very well with noble metals such as Au and Ag, but is not compatible with more frequently used, yet less stable metals such as Cu and Ni. Even though there has been a major shift of research focus from Ag to Cu in recent years, inks for making high-quality Cu or Ni conductors at low-temperature and in the air atmosphere are yet to be developed. 3) The metal conductors made by the "metal ink" method are more suitable for interconnects but are less suitable for electrode applications due to the high roughness and impurity of the metal film. 4) Penetration of the "metal ink" into highly porous substrates or structures with small gaps is The rapid development of flexible and wearable electronics favors low-cost, solution-processing, and high-throughput techniques for fabricating metal contacts, interconnects, and electrodes on flexible substrates of different natures. Conventional top-down printing strategies with metal-nanoparticleformulated inks based on the thermal sintering mechanism often suffer from overheating, rough film surface, low adhesion, and poor metal quality, which are not desirable for most flexible electronic applications. In recent ...

show abstract

Section: Working Principle Of Pamdmentioning

confidence: 99%

Polymer‐Assisted Metal Deposition (PAMD) for Flexible and Wearable Electronics: Principle, Materials, Printing, and Devices

2019

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Therefore, the multidimensional positioning of nanoparticle can tailor the architecture properties. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Therefore, the multidimensional positioning of nanoparticle can tailor the architecture properties.…”

Section: Colloidal Particlesmentioning

confidence: 99%

“…To enhance the ability of directing nanoparticles into an ordered architecture through the capillary assembly, several strategies have been developed. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Therefore, the multidimensional positioning of nanoparticle can tailor the architecture properties. [49] However, this strategy primarily focuses on the fabrication of 2D architectures, which is restricted by its growth orientation.…”

mentioning

confidence: 99%

Manipulation of Colloidal Particles in Three Dimensions via Microfluid Engineering

et al. 2018

View full text Add to dashboard Cite

The assembly of nanoparticles into ordered 3D architectures, which requires more complex spatial arrangements of nanoparticles than 2D, is essential to develop new nano- or microdevices in the fields of biotechnology, magnetic devices, catalysis, and optoelectronics. However, because of the long-distance interactions among the nanoparticles or the applied external force, the movement of nanoparticles cannot be precisely controlled, particularly in multidimensional architectures. Therefore, controlling the 3D architecture remains challenging. In this study, the 3D architecture engineering of colloidal particles by manipulating the microfluid morphology is reported, which produces controllable cross-sections and shapes. The modification of the microfluid morphology, which can be achieved by tuning the physical parameters of the system and the pinning point number, affects the nucleation location, growth rate, and orientation of the architectures. Because of the controllable morphology, the waveguiding distance and direction of 3D architectures can be manipulated. Thus, this study highlights the opportunity for creating morphology-controlled 3D architectures with potential applications in optoelectronics.

show abstract

“…The fabrication of flexible conductive materials is one critical step for realizing these devices. Currently, most flexible conductive materials are made by coating metallic layers (Au, Ag, Cu, and Ni) on flexible substrates such as textiles, polyethylene terephthalate (PET) films, poly(dimethylsiloxane) (PDMS), sponges, and plant leaves . Compared with other metal coating candidates, nickel and copper are still considered as the best materials because of their low cost and high electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

A Nature‐Inspired, Flexible Substrate Strategy for Future Wearable Electronics

Zhu

Chalmers

Chen

et al. 2019

Small

View full text Add to dashboard Cite

Flexibility plays a vital role in wearable electronics. Repeated bending often leads to the dramatic decrease of conductivity because of the numerous microcracks formed in the metal coating layer, which is undesirable for flexible conductors. Herein, conductive textile‐based tactile sensors and metal‐coated polyurethane sponge‐based bending sensors with superior flexibility for monitoring human touch and arm motions are proposed, respectively. Tannic acid, a traditional mordant, is introduced to attach to various flexible substrates, providing a perfect platform for catalyst absorbing and subsequent electroless deposition (ELD). By understanding the nucleation, growth, and structure of electroless metal deposits, the surface morphology of metal nanoparticles can be controlled in nanoscale with simple variation of the plating time. When the electroless plating time is 20 min, the normalized resistance (R/R0) of as‐made conductive fibers is only 1.6, which is much lower than a 60 min ELD sample at the same conditions (R/R0 ≈ 5). This is because a large number of unfilled gaps between nanoparticles prevent metal films from cracking under bending. Importantly, the Kelvin problem is relevant to deposited conductive coatings because metallic cells have a honeycomb‐like structure, which is a rationale to explain the relationships of conductivity and flexibility.

show abstract

Microfluidic Patterning of Metal Structures for Flexible Conductors by In Situ Polymer‐Assisted Electroless Deposition

Cited by 41 publications

References 38 publications

Polymer‐Assisted Metal Deposition (PAMD) for Flexible and Wearable Electronics: Principle, Materials, Printing, and Devices

Polymer‐Assisted Metal Deposition (PAMD) for Flexible and Wearable Electronics: Principle, Materials, Printing, and Devices

Manipulation of Colloidal Particles in Three Dimensions via Microfluid Engineering

A Nature‐Inspired, Flexible Substrate Strategy for Future Wearable Electronics

Contact Info

Product

Resources

About