Abstract:
An exemplary printable composition comprises a liquid or gel suspension of a plurality of metallic nanofibers or nanowires; a first solvent; and a viscosity modifier, resin, or binder. In various embodiments, the metallic nanofibers are between about 10 microns to about 100 microns in length, are between about 10 nm to about 120 nm in diameter, and are typically functionalized with a coating or partial coating of polyvinyl pyrrolidone or a similar compound. An exemplary metallic nanofiber ink which can be printed to produce a substantially transparent conductor comprises a plurality of metallic nanofibers; one or more solvents such as 1-butanol, ethanol, 1-pentanol, n-methylpyrrolidone, cyclohexanone, cyclopentanone, 1-hexanol, acetic acid, cyclohexanol, or mixtures thereof; and a viscosity modifier, resin, or binder such as polyvinyl pyrrolidone or a polyimide, for example.
Abstract:
In one embodiment, an authentication area on a portable object comprises a random arrangement of printed LEDs and a wavelength conversion layer. The object to be authenticated may be a credit card, casino chip, or other object. When the LEDs are energized during authentication of the object, the emitted spectrum and/or persistence of the wavelength conversion layer is detected and encoded in a first code, then compared to valid codes stored in the database. If there is a match, the object is authenticated. The LED power may be remotely inductively coupled and may flash the LEDs, while the wavelength conversion layer emission slowly decays during its optical detection. The flash of blue LED light may be emitted from the edges of the object, which may act as a light guide, for optical feedback to the user that the object is being authenticated.
Abstract:
An exemplary printable composition of a liquid or gel suspension of diodes generally includes a plurality of diodes, a first solvent and/or a viscosity modifier. An exemplary apparatus may include: a plurality of diodes; at least a trace amount of a first solvent; and a polymeric or resin film at least partially surrounding each diode of the plurality of diodes. Various exemplary diodes have a lateral dimension between about 10 to 50 microns and about 5 to 25 microns in height. Other embodiments may also include a plurality of substantially chemically inert particles having a range of sizes between about 10 to about 50 microns.
Abstract:
A representative printable composition comprises a liquid or gel suspension of a plurality of metallic particles; a plurality of semiconductor particles; and a first solvent. The pluralities of particles may also be comprised of an alloy of a metal and a semiconductor. The composition may further comprise a second solvent different from the first solvent. In a representative embodiment, the first solvent comprises a polyol or mixtures thereof, such as glycerin, and the second solvent comprises a carboxylic or dicarboxylic acid or mixtures thereof, such as glutaric acid. In various embodiments, the metallic particles and the semiconductor particles are nanoparticles between about 5 nm to about 1.5 microns in any dimension. A representative metallic and semiconductor particle ink can be printed and annealed to produce a conductor.
Abstract:
Relatively small, electrically isolated segments of LED light sheets are fabricated having an anode terminal and a cathode terminal. The segments contain microscopic printed LEDs that are connected in parallel by two conductive layers sandwiching the LEDs. The top conductive layer is transparent. Separately formed from the light sheet segments is a flexible, large area conductor backplane having a single layer or multiple layers of solid metal strips (traces). The segments are laminated over the backplane's metal pattern to supply power to the segment terminals. An adhesive layer secures the segments to the backplane. The metal pattern may connect the segments in series, or parallel, or form an addressable circuit for a display. The segments may be on a common substrate or physically separated from each other prior to the lamination.
Abstract:
In one embodiment, a security label comprises a random arrangement of printed LEDs. During fabrication of the label, the LEDs are energized, and the resulting dot pattern is converted into a unique digital first code and stored in a database. The label is then attached to an object to be later authenticated, or the LEDs are printed directly on the object, such as a passport, license, bank note, certificate, etc. For authenticating the object, the LEDs are energized and the dot pattern is converted into a code. The code is compared to the first code stored in the database. If there is a match, the object is authenticated. The label may also have a printed second code associated with the first code, and both codes must match codes stored in the database for authentication. The general shape of the printed pattern may convey the proper orientation of the pattern.
Abstract:
On a flexible substrate is printed LEDs and a driver circuit containing transistors. The LEDs and transistors are printed microscopic devices contained in an ink. The LEDs are printed in groups and connected in parallel, and the transistors are printed in groups and connected in parallel. Other components, such as resistors and an on/off switch, are also printed to form the driver. A battery and other circuit components may also be printed on the substrate. An overlay is provided over the LEDs to create a desired light pattern. The LEDs and driver may be generic, and the overlay customizes the light pattern for a particular application. The transistors in the driver may be interconnected with a trace pattern to drive the LEDs in a customized manner, such as for an insert in a product package for marketing to a consumer.
Abstract:
An energy storage device includes a printed current collector layer, where the printed current collector layer includes nickel flakes and a current collector conductive carbon additive. The energy storage device includes a printed electrode layer printed over the current collector layer, where the printed electrode layer includes an ionic liquid and an electrode conductive carbon additive. The ionic liquid can include 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mimBF4). The current collector conductive carbon can include graphene and the electrode conductive carbon additive can include graphite, graphene, and/or carbon nanotubes.
Abstract:
An exemplary printable composition of a liquid or gel suspension of diodes comprises a plurality of diodes, a first solvent and/or a viscosity modifier. An exemplary method of fabricating an electronic device comprises: depositing one or more first conductors; and depositing a plurality of diodes suspended in a mixture of a first solvent and a viscosity modifier. Various exemplary diodes have a lateral dimension between about 10 to 50 microns and about 5 to 25 microns in height. Other embodiments may also include a plurality of substantially chemically inert particles having a range of sizes between about 10 to about 50 microns.
Abstract:
The present invention provides an electronic apparatus, such as a lighting device comprised of light emitting diodes (LEDs) or a power generating apparatus comprising photovoltaic diodes, which may be created through a printing process, using a semiconductor or other substrate particle ink or suspension and using a lens particle ink or suspension. An exemplary apparatus comprises a base; at least one first conductor; a plurality of substantially spherical or optically resonant diodes coupled to the at least one first conductor; at least one second conductor coupled to the plurality of diodes; and a plurality of substantially spherical lenses suspended in a polymer attached or deposited over the diodes. The lenses and the suspending polymer have different indices of refraction. In some embodiments, the lenses and diodes have a ratio of mean diameters or lengths between about 10:1 and 2:1. The diodes may be LEDs or photovoltaic diodes, and in some embodiments, have a junction formed at least partially as a hemispherical shell or cap.