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Table of Contents
Contents
Generalities
Challenges
- Performance requirements
- Force Control in Displacement (>1 cm
- Smoothness, minimum vibration needed to perceive a stimulus (ideal 250Hz
- Speed and Bandwidth: Response time (<1 sec
- Resolution (<3 cm
- Fabrication issues
- Parts (< 10 euro/taxel
- Labor (??
- Assembly (time and difficulty
- Durability (child-proofness
- Maintenance
- Efficiency: Power consumption
- Quiescent power consumption should be low
- Active power consumption should be not too high
- Especially for electrical actuators (<10W?
- Consider limiting the number of possibly simultaneously active taxels to <100%
- Heat dissipation (see Power above
- Safety
- Physical Dimension
Prototype Materials Supply
Actuators
(More information, links, and specifics on these below
SMA
http://www.mondotronics.com/catalog/list.asp?cid=50
- Demo kit $20
- Mondotronix Electric Piston SMA actuators:
http://www.mondotronics.com/catalog/list.asp?cid=42
- A 5-pack costs $100 = $20 x 5. Presumably in volume we could do better.
- Mondotronix Nanomuscle actuators:
http://www.mondotronics.com/catalog
- Mondotronix Bulk SMA Filament/NiTi Springs/Etc:
Pneumatic
* NIL
[[http://www.anver.com/document/bottling_end-effectors/end_effect_ip_series.htm]] * (http://www.anver.com/document/bottling_end-effectors/end_effect_ip_series.htm
- Air Bladder Actuators
* NIL
[[http://www.anver.com/document/bottling_end-effectors/hi_res_end_effect_pic.htm]] * (http://www.anver.com/document/bottling_end-effectors/hi_res_end_effect_pic.htm
- Bottling Pick-Up Actuators
- Unlike some similar products, these might be cheap enough.
[[http://www.shadow.org.uk/products/airmuscles.shtml]]
* (http://www.shadow.org.uk/products/airmuscles.shtml
[[http://www.mutr.co.uk/Pneu/Pneu_musc.htm
* Shadow model is available here:
http://www.mutr.co.uk/Pneu/Pneu_musc.htm
- Shadow Air Muscles
Create this topic(?)http://www.imagesco.com/catalog/airmuscle/AirMuscle.html
- In single quantities, $17 plus $18 for a (SMA-based) valve.
- Another model
- Air Muscles
RC Servo
Insect Robot resources:
SMA
http://www.cimss.vt.edu/shape_memory_database.html
http://www.alloys-metals-ez.com/alloys-metals/0005023_0015665_1.html
- Shape Memory Alloy Manufacturer's Databases:
- L'image:
- Mondotronix electric piston SMA actuators:
- Activation requires about 1V/5A (5W
- 2 cm throw
- Moderate actuation time should allow some rough positioning.
- *Very** * sturdy looking.
- *Temperature**Actuation time * Drawbacks: (hot, 60-90C),
(Several seconds
- Conclusion: Tricky balance between power, heat, and actuation time.
- L'image:
- Nanomuscle SMA actuators
- L'image:
- “Air Muscles”
- Changes resistance as it stretches (100 Ohm/cm
- The Merlin stretch sensor:
only
This last item raises an interesting possibility that would be quite easy to implement: displacement of Wall1 at x1,y1 relative to equilibrium is z1. Suppose we fix wall 2 at x2, y2 to be z2 = -z1 always. Provided the air muscles may be freely pressed upon and contracted by the users, no additional pressure sensor would be needed (and no protection), and the
taxel components we would need are these:
- Small air muscle (Maybe $10 at 1ea
- Stretch sensor ($15 at 1ea
- Electrically controlled valve ($15 at 1ea
- Microcontroller or similar (to scan displacement and balance
- Compression
- Noise
- Valve cost
- Possible problems:
Piezo
}} ===== RC Servo ===== [[http://www.mondotronics.com
- Mondotronix servo kits:
- Many other RC servo suppliers
[[http://www.geocities.com/BourbonStreet/3220/servobasics.html
* RC servo basics:
http://www.geocities.com/BourbonStreet/3220/servobasics.html
* Une Image:
Electric other
- Another Linear push-rod actuator from the same company :
- These are used in slat/blind adjustment, tilting things, etc. Has many great features and options, but, again, suspect power consumption (operating at 24V DC or 230V AC) may be too high.
- a good page with an overview of manufacturers of EAP (Elelectroactive Polymers):
http://ndeaa.jpl.nasa.gov/nasa-nde/lommas/eap/EAP-material-n-products.htm
http://www.environmental-robots.com/
- An offshoot of a U. New Mexico research lab
- Allegedly makes electroactive polymer actuators
- Environmental Robots Inc.
Sensors
http://www.rhodeschroma.com/?id=pressuresensor
*
- Notes regarding the construction of a pressure-sensing matrix such as an electronic keyboard:
- Force-sensing resistor . Some manufacturers:
Create this topic(?)http://www.start.t.u.-tokyo.ac.jp/~kazuto/ * - measuring both magnitude and direction of force: http://www.start.t.u.-tokyo.ac.jp/~kazuto/ [[http://www.eleksen.com/ * electex - pressure, bend/stretch sensors made from washable fabric: http://www.eleksen.com/ [[http://www.empa.ch/plugin/template/empa/41/9517/---/l=2 * active piezoelectric composites for adaptive material systems (both sensing and actuation): http://www.empa.ch/plugin/template/empa/41/9517/---/l=2 * tactile sensing [[http://www.sensorprod.com/ * tactile pressure sensors: http://www.sensorprod.com/ ===== Other Sensor Tech ===== [[SensorTechnology
Control
http://www.dmx512-online.com/links.html
* DMX links:
http://www.dmx512-online.com/links.html
[[http://www.parallax.com
* Basic stamp:
http://www.parallax.com
[[http://www.c-control.de/eng/index.html
* Conrad's c-control microcontroller:
http://www.c-control.de/eng/index.html
====== Membrane ======
==== shock absorption ====
[[http://www.technogel.it
* technogel (PU, non toxic): shock absorbant, shape memory, balanced pressure distribution, does not harden or age, can withstand 300000 pressure cycles without deformation; does not expand:
http://www.technogel.it
[[http://www.edizone.com/technologies.html
* fluid foam (floam and z-flo), gelastic, intelligel:
http://www.edizone.com/technologies.html
http://www.liquicell.com/technology.html * liquicell: combination of a low viscosity fluid and strategically placed seal points that control the flow of liquid: http://www.liquicell.com/technology.html [[http://www.gelconcepts.com/ * different visco-elastic gels: http://www.gelconcepts.com/ ==== stretchable materials ==== [[http://www.shawmutcorporation.com/markets/custom_solutions.php * darlexx: Darlexx® Stretch Barrier Laminates Darlexx® is an omni-directional spandex warp knit with a layer of a highly breathable elastic monolithic membrane. Windproof, waterproof, and breathable, Darlexx® provides solutions across a broad spectrum of end-product applications, such as warm water diving suits, ski racing suits, clean room hoods, boots, and gloves. Darlexx® comes in a 2-ply or 3-ply construction. http://www.shawmutcorporation.com/markets/custom_solutions.php [[http://www.accratec.com/cdxa.htm * CDXA Elastic laminate composite: A breathable, stretch, 3-layer laminate consisting of a nonwoven base, elongated strands of Lycra® XA® ( a man-made elastomeric fiber), and a nonwoven cover, bonded together with a hot melt adhesive. There are two types: MDXA in which the Lycra XA strands are laid down in the machine direction, which gives the resulting laminate good elasticity in the machine direction; and CDXA in which the elongated strands are laid down in the cross-machine direction, which gives the resulting laminate good stretch and recovery in the cross direction plus strength and stability in the machine direction. Both of these elastic laminate composites can be tailored to suit individual applications. http://www.accratec.com/cdxa.htm * Filltext powerspan and nyspan: powerspan is developed by using high tenacious yarn and elastic yarn, and designed for high abrasion resistance and Stretchability. suitable for work gloves, bags and heavy garments. [[http://www.filltex.com/channel_02/powerspan.htmlhttp://www.filltex.com/channel_02/nyspan.html Create this topic(?)http://www.sherwoodtech.com/ChemiThermal.asp * ink from Sherwood technology: http://www.sherwoodtech.com/ChemiThermal.asp [[http://www.hallcrest.com/ * microencapsulation and liquid crystals from: http://www.hallcrest.com/ [[http://www.pilotnbd.com/metamo.htm * metamo colour: http://www.pilotnbd.com/metamo.htm [[http://www.mutr.co.uk/prodDetail.aspx?prodID=574 * thermocolour sheet: http://www.mutr.co.uk/prodDetail.aspx?prodID=574 [[http://www.siltex.com.cn/prode2.htm * multicolour thermocromic pigment: http://www.siltex.com.cn/prode2.htm * Security & Specialty inks from Chromagen corporation : Thermochromic ink(reversible, irreversible), Photochromic ink, Thermochromic Liquid Crystal ink, UV-Phosphour ink, IR ink, Fluorscent ink(Numbering ink), Magnetic ink, Conductive ink, Fugitive ink, Optical Variable ink, Solvent Reactive ink, Chemical Reactive ink, Coin ink(Rubbing ink), Other Security and Specialty ink, Hydrochromic ink, Organic Phosphour ink, UV-IR Absorbing ink r. Blacklight ink, Piezochromic ink, Electrochromic ink, Optoelectrochromic ink, Flavour & Flavour ink, Phase Change Material, Glow in the dark ink Company details: * Name of company : Chromagen Corporation * Address : #202, 218-11, Jangwi 1-Dong, Sungbuk-Ku * Seoul Korea 136-834 * Tel : +82-2-943-1685 * Mobile : +82-(0)16-9816-8580 ( 24 hours open * Fax : +82-2-472-9107 * E-mail : chromagen (at) yahoo (dot) co (dot) kr Rachel received a data sheet for their piezochromic ink [[Active MaterialFlexible Displays
also see Active Materials , Flexible Displays , Materials Textiles and http://open.loop.ph/
More potentially useful stuff
Electronic Supplies and Parts
Animatronics
These are based either on near-field ultrasound tracking, as in mimio http://www.mimio.com
, or on extremely skewed video acquisition. I had in mind the latter, thinking that it might be possible to use video acquisition, with the touchable surface, say, separated from a coated translucent hard sheet of acrylic or something, so that pressure upon the material causes certain regions of the sheep to appear darker (or lighter) than others. Or, in any case, arranging things such that a pattern of light and dark is what would result from pressure upon the surface.
Air or liquid pressure
I was thinking the same could be accomplished with a network of air or liquid filled tubing. http://content.honeywell.com/sensing/prodinfo/pressure
Pressure sensors are small but not necessarily cheap http://content.honeywell.com/sensing/prodinfo/pressure
In a woven array, if we scan, we would only require 2N pressure sensors per wall, where N is the number of taxels along one direction (say, 30-200), but this only locates an isolated centroid. More is possible, as evidenced by http://www.tactex.com
LCD display technology
We might be able to adopt an array based scanning scheme as used in LCDs. See Flexible Displays
for more information on new LCD, OLED and other technologies.
Tactile compression
- Apply a mechanical data compression algorithm
- Apply nonuniform sampling
A Boundary-tensioned mesh
- Could a mesh could be constructed of passive cells which displace only when a tension is applied along both the x and y axes?
Thermal Displays
- temperature can aid a lot in the perception of touch. This extremely interesting research area has not yet yielded satisfactory results for purposes of tactile shape recognition up to the beginning of 2004.
Humidity Displays
- how do we know if the person on the other side of the display is nervous, or has just entered the house after a massive rain-pour?
[[ActuatorTable.xls]]
* ActuatorTable.xls