Electrically conductive materials may be combined with physical computing interfaces to yield a prodigious variety of technomantic designs. I believe this is one of the greatest untapped potentials for cybermagic and electric wizardry today; especially for designing magician-computer interactions that respond to the presence of objects of power or actions performed with them.
Here I shall loosely define a power object as any material thing imbued with occult dynamis such that its presence within a ritual or other magical space is sufficient to amplify the magic therein. Although certain actions may be performed with it, it is usually seen as possessing a magical agency or potency of its own, either inherent in the shape or materials from which it is manufactured (by human or nature), or because occult agency or potency was transferred to it via ritual or other event (such as having belonged to someone special or having existed in a special place or time—cf. magical contagion). Typical examples of traditional power objects include jewelry such as amulets and rings; talismans; idols, effigies, and other “graven images”; and animal fetishes such as are constituted of teeth, claws, bone, fur, or feathers.
Below is a brief animation showing diverse conductive objects interacting with a simple project via Makey Makey Classic. When an object touches both strips of copper tape, thus closing the circuit, Scratch responds by changing the red, inverted pentagram to a green, upright pentagram. The objects include a lock of hair tied with conductive thread; a Mercury dime; Baphomet ring, play-dough skull; and play-dough hand holding a consecrated bead of uranium glass (i.e., a conductive object supporting a non-conductive object, like the thread around the hair).
Metals are good conductors hence they are commonly used in electrical wiring. Power objects—including many traditional ones such as rings, pendants, and daggers—may be casted or forged in metal, and metal wires and fasteners can connect objects to interfaces. Although some metals conduct electricity better than others, any should work fine with the interfaces mentioned in Technomancy 101.
An ohmmeter, which is included in most multimeters, is helpful for determining whether or not an object is electrically conductive, by measuring how electrically resistant it is: if it has low resistance, then it is a good conductor. Check out this SparkFun tutorial for instructions on using a multimeter.
Conductive thread made of thin strands of steel of silver is typically more flexible than wire (steel is a little stiffer, but silver oxidizes which increases its resistance over time), and may be sewn into paper or fabric. Wrapping a non-conductive object in conductive thread often suffices to connect that object to an interface.
- Conductive thread tutorial @ Adafruit
- More wearables tutorials @ Adafruit
- Wearable electronics @ Adafruit
- LilyPad Basic: E-Sewing @ SparkFun
- More wearables tutorials @ SparkFun
- E-Textiles @ SparkFun
Sigils and other graphical devices inscribed in conductive paint or ink (you can even draw them with a graphite pencil) have a wide range of creative applications in the occult arts. Conductive paint may be brushed or screen-printed onto various surfaces, and you can mix in arcane liquids such as St. Cyprian ink; or dragon’s blood, dove’s blood, or bat’s blood ink; or small quantities of solid material.
Connecting sigils drawn on paper or parchment to an electronic interface usually requires attaching wires or conductive thread. If using crocodile clips to connect a sigil to Makey Makey or a PicoBoard, Book Darts work well to protect the paper (I prefer the stainless steel ones), but common paper clips work as well (although some have a protective coating you will need to remove with a blade or sandpaper), and many more ornamental solutions are possible. You can also just use the paint itself or a conductive glue to fasten wires or thread to the sigil.
You can use conductive dough to sculpt figures of people or other things, inscribe magical words or symbols, or take impressions from various objects. You can make your own or use the commercial stuff, and mix in small quantities of essential oils or other arcane materials. Insulating (a.k.a. resistive) dough may be paired with conductive dough to make more complex circuits. Be sure not to let conductive dough dry too much; its conductivity depends on moisture.
Scholastic makes a Circuit Clay that does the same kind of thing but holds its shape a little better than dough. You can also sculpt idols, effigies, and other objects from ordinary clay, let the clay dry, then insert wire through it, wrap conductive thread around it, coat it in conductive paint, &c., to make it interactive.
Water typically has low conductivity compared to, say, copper wire, but it is more conductive than air, so you can detect when it has been connected to an interface, typically by submerging a pair of electrodes into a container holding the liquid.
You can improve water’s conductivity by increasing its salinity, i.e., by adding salt, which increases the concentration of ions in the water; see “Ye Essential Saltes” for more information. Amalgamate with oils, herbs, or other materials as appropriate to make elixirs, potions, philtres, &c., that can interact with the computer, keeping in mind that passing a direct current through water will produce polarization and electrolysis; again see “Ye Essential Saltes” for more info.
Makey Makey’s capacitive touch sensors are sensitive to many organic materials, even (more or less fresh) fruits, vegetable, flowers, and leaves. They usually respond well to contact with skin, although in arid climates you may need to lightly moisten the skin’s surface.
Electrically conductive and resistive materials are used in the manufacture of electronic components, several of which may be used with Scratch’s physical computing interfaces.
The PicoBoard’s resistance sensors use 5 volts of electricity to measure resistance, and that 5V can power an LED. Since you need a resistor in series with the LED, when you connect the LED + resistor to the board, the resistance change is measurable and detectable in Scratch. Thus you can attach an LED + resistor to a non-conductive object, and when you connect the object to the interface, not only will Scratch respond by doing whatever you have programmed it to do, but the LED will illume giving you an immediate visual sign of the object’s connectivity. I like the LilyPad LED packages because they have built-in resistors and work well with conductive wire, tape, thread, and paint.