Abstract: In exemplary implementations of this invention, a shape controller controls the shape of a bladder as the bladder inflates. The shape controller includes a first set of regions and a second set of regions. The second set of regions is more flexible than the first set of regions. The shape controller is embedded within, or adjacent to, a wall of the bladder. When the bladder is inflated, the overall shape of the bladder bends in areas adjacent to the more flexible regions of the shape controller. For example, the shape controller may comprise paper and the more flexible regions may comprise creases in the paper. Or, for example, the more flexible regions may comprise notches or indentations. In some implementations of this invention, a multi-state shape display changes shape as it inflates, with additional bumps forming as pressure in the display increases.

Abstract: In some implementations, bending or other shape changes of a device are actuated by inflating or deflating a bladder in the device. Then, once the desired new shape is achieved by this actuation, another bladder in the device is layer-jammed, to make the device rigid in the new shape. In some cases, sheets in the layer-jamming bladder are coated with abrasive particles. In some cases, layer jamming bladders are interwoven to form a woven device. The rigidity of the woven device can be anisotropically controlled. Layer jamming some, but not all, of the bladders in the woven device causes the woven device to have a rigidity that varies by direction. In some cases, a layer-jamming bladder includes a solid layer with a crease in it. As a result, the bladder can easily bend at the crease.

Abstract: A computer produces a digital model that efficiently describes a dense array of many micro-pillars. The digital model achieves this efficiency by describing an entire micro-pillar with only a few parameters. For example, an entire micro-pillar may be described by two of more of the following parameters: height, base thickness, profile and tilt. The computer outputs instructions to fabricate the micro-pillar array, in accordance with the digital model. A 3D printer fabricates the micro-pillar array, based on the instructions. Applying vibration to a directional array of micro-pillars may cause the array of micro-pillars to actuate motion of a passive object that is touching the array. Also, a sensor may measure sounds caused by swipes against a micro-pillar array, and output signals indicative of the measurements. A computer performs a machine learning algorithm that takes the measurements as an input, and classifies the swipes.

Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, facilitate the design and use of 3D printed auxetic structures. In one aspect, a system includes one or more computer storage media having instructions stored thereon; and one or more data processing apparatus configured to execute the instructions to perform operations including (i) receiving an input specifying a three dimensional (3D) model of a 3D structure that includes at least two different materials having a predefined arrangement with respect to each other to give the 3D structure a negative Poisson ratio, (ii) receiving an input regarding a change for the 3D structure, and (iii) modifying the predefined arrangement of the at least two different materials with respect to each other in response to the input regarding the change.

Abstract: A composite film includes a substrate that is not responsive to relative humidity, and also one or more layers of hygromorphic material. The hygromorphic material expands in response to an increase in relative humidity and contracts in response to a decrease in relative humidity. In some cases, the composite film is bi-layer or tri-layer. The composite films are fabricated such that they undergo a desired bending pattern in response to changes in relative humidity. In some cases, these bending patterns are combinations of two bending primitives: a smooth curve and a sharply angled curve. These two primitives are combined to create a variety of shape transformations including 1D linear transformation, 2D surface expansion and contraction, 2.5D texture change and 3D folding. Any type of hygromorphic material may be employed, including living gram positive and gram negative bacterial cells, yeast cells, plant cells, mammalian cells, cell debris, or hydrogel.

Abstract: In some implementations, bending or other shape changes of a device are actuated by inflating or deflating a bladder in the device. Then, once the desired new shape is achieved by this actuation, another bladder in the device is layer-jammed, to make the device rigid in the new shape. In some cases, sheets in the layer-jamming bladder are coated with abrasive particles. In some cases, layer jamming bladders are interwoven to form a woven device. The rigidity of the woven device can be anisotropically controlled. Layer jamming some, but not all, of the bladders in the woven device causes the woven device to have a rigidity that varies by direction. In some cases, a layer-jamming bladder includes a solid layer with a crease in it. As a result, the bladder can easily bend at the crease.

Abstract: In exemplary implementations of this invention, a shape controller controls the shape of a bladder as the bladder inflates. The shape controller includes a first set of regions and a second set of regions. The second set of regions is more flexible than the first set of regions. The shape controller is embedded within, or adjacent to, a wall of the bladder. When the bladder is inflated, the overall shape of the bladder bends in areas adjacent to the more flexible regions of the shape controller. For example, the shape controller may comprise paper and the more flexible regions may comprise creases in the paper. Or, for example, the more flexible regions may comprise notches or indentations. In some implementations of this invention, a multi-state shape display changes shape as it inflates, with additional bumps forming as pressure in the display increases.