Abstract:
A security device that elicits at least one dynamic response upon acceleration, or upon change of orientation with respect to gravity, wherein the dynamic response continues after cessation of the acceleration or the change of orientation. In addition, the dynamic response can be optical, such that it is visually observable by an unaided human eye. Alternatively, the response can be machine readable. In some cases, the dynamic response has duration of from about 0.01 s to about 100 s, or from about Is to about 10s.
Abstract:
Gravitational Janus microparticle having, a center-of-mass, a center-of-volume, and a non-uniform density, wherein: the center-of-mass and the center-of-volume are distinct. When suspended in a fluid, the microparticle substantially aligns with either: i) the gravitational field; or ii) the direction of an acceleration, such that the Janus microparticle is in substantial rotation equilibrium. After perturbation from substantial rotational equilibrium, the Janus microparticle reversibly rotates to return to substantial rotational equilibrium. The gravitational Janus microparticle may comprise at least two portions, each having distinct physical and/or chemical characteristics, wherein at least one portion provides a detectable effect following rotation and alignment of the microparticle.
Abstract:
Gravitational Janus microparticle having, a center-of-mass, a center-of-volume, and a non¬ uniform density, wherein: the center-of-mass and the center-of-volume are distinct. When suspended in a fluid, the microparticle substantially aligns with either: i) the gravitational field; or ii) the direction of an acceleration, such that the Janus microparticle is in substantial rotation equilibrium. After perturbation from substantial rotational equilibrium, the Janus microparticle reversibly rotates to return to substantial rotational equilibrium. The gravitational Janus microparticle may comprise at least two portions, each having distinct physical and/or chemical characteristics, wherein at least one portion provides a detectable effect following rotation and alignment of the microparticle.
Abstract:
There is disclosed a microscale or nanoscale stepper motor in which one or more arrays of corresponding types of optically switchable molecular actuators are used to drive progressive motion between bodies of the motor.
Abstract:
A security device that elicits at least one dynamic response upon acceleration, or upon change of orientation with respect to gravity, wherein the dynamic response continues after cessation of the acceleration or the change of orientation. In addition, the dynamic response can be optical, such that it is visually observable by an unaided human eye. Alternatively, the response can be machine readable. In some cases, the dynamic response has duration of from about 0.01 s to about 100 s, or from about Is to about 10s.