44 research outputs found
Black Silicon/Elastomer Composite Surface with Switchable Wettability and Adhesion between Lotus and Rose Petal Effects by Mechanical Strain
Although many recent studies demonstrate
surfaces with switchable wettability under various external stimuli,
a deliberate effort to self-propel liquid droplets utilizing a surface
wetting mode switch between slippery lotus and adhesive rose petal
states via a mechanical strain has not been made yet, which would
otherwise further benefit microfluidic applications. In this work,
we present a black silicon/elastomer (bSi/elastomer) composite surface
which shows switchable wettability and adhesion across the two wetting
modes by mechanical stretching. The composite surface is composed
of a scale-like nanostructured silicon platelet array that covers
an elastomer surface. The gap between the neighboring silicon platelets
is reversibly changeable as a function of a mechanical strain, leading
to the transition between the two wetting modes. Moreover, the composite
surface is highly flexible although its wetting properties primarily
originate from superhydrophobic bSi platelets. Different wetting characteristics
of the composite surface in various mechanical strains are studied,
and droplet manipulation such as droplet self-propulsion and pick-and-place
using the composite surface is demonstrated, which highlights its
potentials for microfluidic applications
Black Silicon/Elastomer Composite Surface with Switchable Wettability and Adhesion between Lotus and Rose Petal Effects by Mechanical Strain
Although many recent studies demonstrate
surfaces with switchable wettability under various external stimuli,
a deliberate effort to self-propel liquid droplets utilizing a surface
wetting mode switch between slippery lotus and adhesive rose petal
states via a mechanical strain has not been made yet, which would
otherwise further benefit microfluidic applications. In this work,
we present a black silicon/elastomer (bSi/elastomer) composite surface
which shows switchable wettability and adhesion across the two wetting
modes by mechanical stretching. The composite surface is composed
of a scale-like nanostructured silicon platelet array that covers
an elastomer surface. The gap between the neighboring silicon platelets
is reversibly changeable as a function of a mechanical strain, leading
to the transition between the two wetting modes. Moreover, the composite
surface is highly flexible although its wetting properties primarily
originate from superhydrophobic bSi platelets. Different wetting characteristics
of the composite surface in various mechanical strains are studied,
and droplet manipulation such as droplet self-propulsion and pick-and-place
using the composite surface is demonstrated, which highlights its
potentials for microfluidic applications
Electrical Contact at the Interface between Silicon and Transfer-Printed Gold Films by Eutectic Joining
This
paper presents the electrical and morphological properties at the
interface between a metal (Au) and a semiconductor (Si) formed by
a novel transfer-printing technology. This work shows that a transfer-printed
thin (hundreds of nanometers) Au film forms excellent electrical contact
on a Si substrate when appropriate thermal treatment is applied. The
successful electrical contact is attributed to eutectic joining, which
allows for the right amount of atomic level mass transport between
Au and Si. The outcomes suggest that transfer-printing-based micromanufacturing
can realize not only strong mechanical bonding but also high-quality
electrical contact via eutectic joining
Microstructured Shape Memory Polymer Surfaces with Reversible Dry Adhesion
We
present a shape memory polymer (SMP) surface with repeatable, very
strong (>18 atm), and extremely reversible (strong to weak adhesion
ratio of >1 Ă— 10<sup>4</sup>) dry adhesion to a glass substrate.
This was achieved by exploiting bulk material properties of SMP and
surface microstructuring. Its exceptional dry adhesive performance
is attributed to the SMP’s rigidity change in response to temperature
and its capabilities of temporary shape locking and permanent shape
recovery, which when combined with a microtip surface design enables
time-independent control of contact area
Easy Synthesis of Hierarchical Carbon Spheres with Superior Capacitive Performance in Supercapacitors
An easy template-free approach to
the fabrication of pure carbon
microspheres has been achieved via direct pyrolysis of as-prepared
polyaromatic hydrocarbons including polynaphthalene and polypyrene.
The polyaromatics were synthesized from aromatic hydrocarbons (AHCs)
using anhydrous zinc chloride as the Friedel–Crafts catalyst
and chloromethyl methyl ether as a cross-linker. The experimental
results show that the methylene bridges between phenyl rings generate
a hierarchical porous polyaromatic precursor to form three-dimensionally
(3D) interconnected micro-, meso-, and macroporous networks during
carbonization. These hierarchical porous carbon aggregates of spherical
carbon spheres exhibit faster ion transport/diffusion behavior and
increased surface area usage in electric double-layer capacitors.
Furthermore, micropores are present in the 3D interconnected network
inside the cross-linked AHC-based carbon microspheres, thus imparting
an exceptionally large, electrochemically accessible surface area
for charge accumulation
An example log for patient journey.
An example log for patient journey.</p
Process mining in the changing HIS environment (adapted based on [21, 26]).
Process mining in the changing HIS environment (adapted based on [21, 26]).</p
Patient journey map using visit-level events.
(a) entire patient journey with all activities included (left) and the enlarged screenshot of the early encounters only (right); (b) patient journey with mainstream behaviors only.</p
Finding the optimal number of clinical orders in TLH CP.
Finding the optimal number of clinical orders in TLH CP.</p