'Electrick' Spray Paint Turns Almost Any Surface Into A Touch Sensor

Created at Carnegie Mellon University, 'Electrick' is a low-cost sensing technique that enables touch input on a wide variety of objects and surfaces. This is achieved by using electric field tomography combined with an electrically conductive material, which can be easily and cheaply added to surfaces. The innovative technique is compatible with common manufacturing methods, such as spray/brush coating, vacuum forming, and casting, enabling a wide range of possible uses and outputs. 'Electrick' can bring touch interactivity to rapidly fabricated objects, including those that are laser cut or 3D printed.

Transcript

00:00:03 [Music] current touch input Technologies are best suited for small and flat applications such as smartphones tablets and kiosks however these Technologies are too expensive to scale to large surfaces such as walls and furniture and are incompatible with objects having irregular and complex geometries such as tools and toys we present electric a

00:00:30 lowcost touch sensing technique for large irregular and rapidly prototyped objects adding touch interactivity to objects is easy first we add a conductive coating to an object then we attach sensing electrodes to the periphery of the desired interactive area an optional top coat can be applied with this setup electric can detect different touch locations as well as

00:01:00 enable course continuous touch tracking our sensing principle works by injecting a small electric current into the conductive layer using a pair of electrodes we then measure the voltage at all other adjacent electrode pairs when a finger touches the surface some current is shunted causing a localized reduction in voltage to better estimate the touch location we rotate the current

00:01:27 emitting pair and repeat this process this results in a mesh of cross-sectional measurements using tomographic reconstruction we can create a 2d touch sensing image revealing finger locations here is a real world version of our Illustrated setup this time using 16 electrodes the tomographic output is visualized on the laptop we can apply

00:01:49 standard computer vision blob tracking techniques to capture finger locations and movement to demonstrate the expressivity and versatility of electric we built a variety of fully functional example applications first there are many solid materials that are compatible with our technique and can be used in Milling molding stamping and other common

00:02:10 manufacturing processes an example material is velostat a carbon loaded poolopen film most typically used for packaging of electronic components velat can be attached to flat surfaces with adhesive to make inexpensive touch panels or when laminated to therm formable sheet fellat can be vacuum formed into a variety of 3D shapes such as a phone case now touch

00:02:37 sensitive the case can detect different user grasps which in turn can launch different applications such as a camera or open the keyboard in a messaging app electric can also enhance the functionality of rapidly prototype objects and experiences for example a designer can use electric to prototype a controller interface using the same static body but with different

00:03:07 interactive control layouts another example material is carbon loaded ABS sold as a filament for 3D printing and also as pellets chiefly for injection molding 3D printing is a particularly powerful prototyping tool however the output is generally static it embodies the desired 3D form but rarely the interactivity of the end product with electric 3D printed

00:03:33 artifacts can be made touch sensitive enabling rapid iteration of both Form and Function second liquid paint and spray Coatings are particularly versatile allowing electric to be applied to existing objects to augment them with touch sensing capabilities for this we use carbon conductive paint primarily used for

00:03:57 electrostatic discharge and RF shielding purposes this can be easily sprayed or painted onto almost any surface flat or irregular and at a variety of sizes for example we spray painted an electric guitar and attach electrodes along the edge of the instrument enabling touch tracking in this demo a user can add custom controls to the guitar body using

00:04:24 a companion laptop application [Music] we use a similar fabrication process on this steering wheel which can detect the location of both hands as well as hand gestures [Music] electric also scales to large surfaces such as this desk

00:05:12 example we brush painted this desktop and attached electrodes to the periphery in this example stickers can be used to bind Table locations to functions on a laptop allowing for quick access [Music] touch input on surfaces as large as walls is also possible we carbon painted a sheet of dry wall which we then

00:05:44 covered with standard latex wall paint in this example light control application tapping the wall toggles the light dragging up or down allows the user to control brightness finally there are also conductive materials that are soft and pliable which are most often used in molded products one example is conductive silicone which we created by mixing

00:06:05 carbon fiber and conventional silicone Judge Me by my size do you May the force be with you with electric it is also possible to use Jello to create touch sensitive objects the occipital lobe is the visual processing center of the mamalian brain finally Play-Doh is also comp comp able with electric in this example a user can sculpt a figure or object and bind sound

00:06:36 effects to different touch [Music] locations don't touch my nose I'm melting I'm melting for more detail and example applications please see our paper