2 research outputs found
Piezopotential-Programmed Multilevel Nonvolatile Memory As Triggered by Mechanical Stimuli
We
report the development of a piezopotential-programmed nonvolatile
memory array using a combination of ion gel-gated field-effect transistors
(FETs) and piezoelectric nanogenerators (NGs). Piezopotentials produced
from the NGs under external strains were able to replace the gate
voltage inputs associated with the programming/erasing operation of
the memory, which reduced the power consumption compared with conventional
memory devices. Multilevel data storage in the memory device could
be achieved by varying the external bending strain applied to the
piezoelectric NGs. The resulting devices exhibited good memory performance,
including a large programming/erasing current ratio that exceeded
10<sup>3</sup>, multilevel data storage of 2 bits (over 4 levels),
performance stability over 100 cycles, and stable data retention over
3000 s. The piezopotential-programmed multilevel nonvolatile memory
device described here is important for applications in data-storable
electronic skin and advanced human-robot interface operations
Petal-Inspired Diffractive Grating on a Wavy Surface: Deterministic Fabrications and Applications to Colorizations and LED Devices
Interestingly, the
petals of flowering plants display unique hierarchical
structures, in which surface relief gratings (SRGs) are conformably
coated on a curved surface with a large radius of curvature (hereafter
referred to as wavy surface). However, systematic studies on the interplay
between the diffractive modes and the wavy surface have not yet been
reported, due to the absence of deterministic nanofabrication methods
capable of generating combinatorially diverse SRGs on a wavy surface.
Here, by taking advantage of the recently developed nanofabrication
composed of evaporative assembly and photofluidic holography inscription,
we were able to achieve (i) combinatorially diverse petal-inspired
SRGs with controlled curvatures, periodicities, and dimensionalities,
and (ii) systematic optical studies of the relevant diffraction modes.
Furthermore, the unique diffraction modes of the petal-inspired SRGs
were found to be useful for the enhancement of the outcoupling efficiency
of an organic light emitting diode (OLED). Thus, our systematic analysis
of the interplay between the diffractive modes and the petal-inspired
SRGs provides a basis for making more informed decisions in the design
of petal-inspired diffractive grating and its applications to optoelectronics