12. SKIN ELECTRONICS¶

Introduction: What Are Skin Electronics?¶

Skin electronics are ultra–body-close, flexible electronic systems designed to be worn directly on the skin—as patches, tattoos, masks, nail designs, or thin textile surfaces. They integrate technology with the body itself & respond to physical signals such as touch, breathing, movement, or biometric changes.

Unlike traditional wearables embedded in clothing, skin electronics exist on the skin, creating an immediate & intimate interface between body & technology. These projects combine elements of e-textiles, soft robotics, biofeedback, performance art, & microcontroller programming.

Learning Objectives of the Assignment¶

This assignment introduces the fundamentals of designing & fabricating skin electronics:

Research Skills: Explore references, artistic works, & scientific publications related to skin interfaces & integrate them conceptually.
Design Skills: Develop your own body-close electronic design, including schematics, sensor/actuator selection, & microcontroller programming.
Fabrication Skills: Build a functional skin circuit & integrate inputs (e.g., sensors) & outputs (e.g., LEDs, motors) into a wearable system.
Process Skills: Document the entire development process—from initial sketches to testing, troubleshooting, & the final prototype.
Final Outcome: Produce a working, battery-powered skin electronic artefact worn on the body & demonstrated in a short video.
Originality: Create a personal & thoughtful design that goes beyond replication & explores new or unconventional ideas.

NFCs¶

┌──────────────────────────────────────────────┐
│                 WHAT IS NFC?                 │
├──────────────────────────────────────────────┤
│ NFC (Near Field Communication) enables       │
│ wireless data exchange over very short       │
│ distances (1–4 cm). It works through         │
│ electromagnetic induction between two        │
│ antennas:                                    │
│                                              │
│ • A reader (phone, tablet, microcontroller)  │
│ • A passive NFC tag (sticker)                │
│                                              │
│ The tag is powered by the reader’s magnetic  │
│ field—no battery required.                   │
└──────────────────────────────────────────────┘
┌──────────────────────────────────────────────┐
│         WHAT AN NFC STICKER CONTAINS         │
├──────────────────────────────────────────────┤
│ • Printed antenna (spiral-shaped)            │
│ • Small memory microchip                     │
│ • Thin, flexible adhesive layer              │
│                                              │
│ These tags are extremely thin and suitable   │
│ for embedding into flexible electronics.     │
└──────────────────────────────────────────────┘
┌──────────────────────────────────────────────┐
│               HOW NFC WORKS                  │
├──────────────────────────────────────────────┤
│  Reader antenna  ───▶  Creates magnetic field│
│                                              │
│  NFC tag antenna ─▶  Harvests energy +       │
│                       exchanges data         │
│                                              │
│ Communication happens only at very close     │
│ range, making it secure and energy-efficient.│
└──────────────────────────────────────────────┘

INSPIRATION¶

ANI LIU¶

Ani Liu is a transdisciplinary artist working at the intersection of art, science, & technology.

Her practice explores how bodies, identities, & forms of care are shaped by technological & social forces. With a background in architecture, design, & research, she combines methods from biotechnology, engineering, & visual art to question how we sense, interact, & exist in the world.

Through installations, objects, & speculative experiments, Liu investigates themes such as gender, reproduction, intimacy, & embodied experience—often using biological material, sensor-based interfaces, & critical storytelling.

ani-liu.com instagram: ani.liu.studio

Mind Controlled Spermatozoa – Ani Liu ¶

Mind Controlled Spermatozoa is an artwork in which Ani Liu uses a brain–computer interface to influence the movement of human sperm cells via electrical fields. By linking EEG signals with galvanotaxis, the project turns mental focus into a direct form of biological control.

Conceptually, the work critically reflects on issues of gender, power, & reproductive politics, transforming scientific procedures into a provocative feminist statement.

The Empathy Machine - Ani Liu ¶

The Empathy Machine: Towards a Networked Sensorium – short summary

The Empathy Machine is an experimental project by Ani Liu that explores how technology can connect the sensory experiences of 2 people. Using camera‐based headsets, participants are able to see through each other’s eyes, temporarily exchanging visual perception.

By linking bodies, senses & technological interfaces, the work challenges ideas of individuality & invites a reflection on empathy, shared experience & the possibility of a “networked” or collective sensorium.

small inconveniences + woman pains - Ani Liu¶

Both works use wearable devices to simulate physical experiences related to pregnancy & childbirth, such as incontinence or labor pain. Ani Liu explores how these bodily realities are culturally hidden, minimized, or romanticized, inviting others to literally feel what is usually invisible.

DUOSKIN - MIT ¶

DuoSkin is an MIT Media Lab project that turns temporary metallic tattoos into functional on-skin interfaces, such as touch controls, displays, or NFC tags. The project shows how the skin itself can become an interactive surface, combining wearable technology with body art.

INSPIRATION: Interactive Museum + Game¶

PHAENO Wolfsburg - Mindgame¶

Mindgame – Move a ball only with your thoughts Mindgame is an interactive exhibit at phaeno Wolfsburg Germany, where visitors can move a small ball using only their mental concentration. Instead of physical contact, the system uses simple brainwave sensors that detect levels of focus, relaxation, or attention. These signals are translated into motion, so the ball begins to move whenever your mind is calm & concentrated enough.

The installation seams like to offers a playful introduction to neurotechnology & biofeedback: it makes the invisible activity of the brain visible & tangible. By experimenting, visitors experience how their own mental state can directly influence a physical object—turning abstract science into an intuitive & engaging experience.

www.phaeno.de

MINDFLEX¶

Mindflex is a commercial “mind control” toy in which a ball seems to move using only your thoughts. In practice, the headset measures very basic electrical activity related to relaxation & concentration, which is used to adjust a small airflow that lifts the ball. The game is fun & surprising, but it oversimplifies brain-computer interaction & can give the impression of real thought-reading, although the underlying technology is quite limited.

Mindflex - Gedankenspiel Spiegle online: Hirnforschung - Aberglaube im Kinderzimmer mindball

TECH INSPIRATION¶

Spire – Breath Tracker ¶

Spire is a small wearable that tracks your breathing patterns & gives alerts when your breath becomes tense or irregular. It’s worn on the waistband or bra & encourages calmer breathing & stress reduction through gentle app feedback.

Prana ¶

Prana is a wearable that tracks your breathing & posture & gives gentle reminders when either becomes unhealthy. It’s designed to help build better breathing habits & body awareness in everyday life.

MUSE – Train your Brain & Find Your Focus ¶

MUSE is a wearable headband + app that helps you train your mind through real-time brainwave feedback.

By measuring brain activity, it detects when your mind is calm or distracted & guides you toward focused, meditative states.

Hexoskin - Smart Clothes ¶

Hexoskin are smart shirts with built-in sensors that track breathing, heart rate & activity in real time, turning everyday clothing into a continuous health monitor.

ASSIGNMENT¶

How to write information to an NFC Sticker using “NFC Tools”¶

what you need:¶

An NFC sticker (e.g. NTAG213/215/216) A smartphone with NFC enabled The NFC Tools app (Android or iOS)

Step 1 – Install the app¶

Open Google Play Store or Apple App Store. Search for “NFC Tools”. Download and install the app.

Step 2 – Turn on NFC¶

iPhone: On newer iPhones, NFC is usually always on. No extra setting needed. / Android: Go to Settings → Connections / Connected devices → NFC and turn it ON.

Step 3 – Open NFC Tools and go to Write¶

Open NFC Tools. Tap the tab “Write” at the top. Tap “Add a record”.

Step 4 – Choose what you want to write¶

In “Add a record”, you’ll see options like: - URL / Web address – open a website - Text – simple note or message - Contact – vCard / contact info - Phone number, Email, WiFi, etc.

Example: Choose “URL / Website” if you want the sticker to open a page.

Step 5 – Enter your information¶

After choosing the record type, fill in the fields: For a URL: e.g. https://yourwebsite.com For Text: e.g. Hello, this is my NFC tag! Tap OK or Validate (depending on your phone). You’ll be back on the Write screen – your record is now listed there. You can add more than one record if you like (e.g. URL + Text).

Step 6 – Write to the NFC tag¶

On the Write screen, tap “Write” or “Write / X bytes”. The app will say something like “Approach an NFC tag”. Hold the back/top of your phone close to the NFC sticker (usually 1–2 cm distance, where the NFC antenna sits). Wait for the vibration / sound / success message: e.g. “Write complete” or “Data written successfully”. Your sticker is now programmed.

Step 7 – Test the NFC sticker¶

Close the NFC Tools app (optional). Tap your phone again on the NFC sticker. Your phone should automatically: open the website, or show the text / contact, etc.

If nothing happens: Check that NFC is enabled. Try a different position on the back/top of your phone. Make sure the tag is not locked or damaged.

Optional – Lock the tag (read-only)¶

If you don’t want anyone to change the data: In NFC Tools, go to “Other” → “Set password / Lock tag” (exact wording may vary). Follow the instructions to lock the tag. !! Once locked, many tags cannot be rewritten – so do this only when you’re sure.

SKIN LINKS¶

On my arm I placed 3 NFC stickers, each loaded with a different digital link.

The 1. sticker opens my personal website, the 2. connects directly to my Skin Electronics assignment on the class.textile-academy.org platform, & the 3. links to a short promotional video for my start-up MUSE LAB.

Together, they turn my skin into a small interactive interface that can be explored simply by tapping with a smartphone.

THE 3. EYE¶

Iris Video – NFC As a next step, I created a short video of my own iris rotating. For this, I manually rotated & aligned multiple iris photographs in Photoshop, exported them as a sequence, & combined them into a video ( in iMovie). I uploaded the video to YouTube as “unlisted” & then stored the link on another NFC sticker.

BLOW¶

What I’m trying to do¶

I’m building a small circuit where my breath becomes an input signal. When I blow onto the Sound Sensor (V1.4), the sensor detects a short sound-peak & sends this value to my microcontroller (XIAO RP2040). If the value is higher than a threshold, the microcontroller turns on an LED.

This creates a very simple “breath-to-light” interaction – as a first test for a body-based electronic interface.

Step-by-step wiring¶

Sound Sensor V1.4 → XIAO RP2040¶

VCC → 5V
GND → GND
OUT → A0 (GPIO26)

The OUT pin gives the analog signal that we read in the code.

LED + 220 Ω resistor → XIAO RP2040¶

Digital Pin D9 → 220 Ω resistor → LED (anode / +)
LED (cathode / –) → GND

The resistor protects the LED from too much current.

Power¶

connect the XIAO RP2040 via USB

This powers the board, the sensor, & the LED, & also allows uploading the code.

Wiring Diagram¶

            +5V  -------------------- VCC (Sound Sensor)
            GND  -------------------- GND (Sound Sensor)
        A0/AN -------------------- OUT (Sound Sensor)

                        (Arduino UNO example)

                                ┌────────────┐
                                │   Arduino  │
                                │            │
    Sound Sensor  ┌────────────►│ A0         │
    (V1.4)        │             │            │
                │  VCC ◄──────│ 5V         │
                │  GND ◄──────│ GND        │
                └─────────────┴────────────┘

            LED circuit:

            Pin 9  ---220Ω---►|---   LED   --- GND

                                +       -

Note on the Code¶

The Arduino code used in this project was developed with support from ChatGPT. I described the desired interaction &hardware setup (XIAO RP2040, Grove Sound Sensor, NeoPixels), & ChatGPT assisted in generating & adapting the code examples based on my requirements.

NeoPixel Test:¶

#include <Adafruit_NeoPixel.h>

#define NEOPIXEL_PIN  D7      // data pin to NeoPixels
#define NUM_PIXELS    4       // you have 4 pixels

Adafruit_NeoPixel pixels(NUM_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
pixels.begin();
pixels.clear();
pixels.show();
}

void loop() {
// Light all pixels in red
for (int i = 0; i < NUM_PIXELS; i++) {
    pixels.setPixelColor(i, pixels.Color(05, 15, 10));
}
pixels.show();
delay(500);
}

THE CODE¶

#include <Adafruit_NeoPixel.h>

// Grove Sound Sensor
const int SOUND_PIN = A0; // S -> A0 (GPIO26)

// external NeoPixels on D7
#define NEOPIXEL_PIN  D7
#define NUM_PIXELS    4   // you said you have 4

Adafruit_NeoPixel pixels(NUM_PIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);

// Settings
int threshold = 300;  // adjust for blowing sensitivity
int delayTime = 30;

void setup() {
Serial.begin(115200);

pixels.begin();
pixels.clear();
pixels.show();

pinMode(SOUND_PIN, INPUT);
}

void loop() {
int soundValue = analogRead(SOUND_PIN);
Serial.println(soundValue);

if (soundValue > threshold) {
    // your color here:
    for (int i = 0; i < NUM_PIXELS; i++) {
    pixels.setPixelColor(i, pixels.Color(5, 15, 10));
    }
    pixels.show();
} else {
    pixels.clear();
    pixels.show();
}

delay(delayTime);
}

soldering¶

Additional Notes on the Construction Process¶

To connect the individual acrylic modules electrically, I used copper tape as conductive traces. I cut the copper tape into very thin strips & soldered the wire connections directly onto the tape ends using a small amount of solder. I really liked the delicate, almost technical look this created—visually.

However, the thin copper tape turned out to be quite fragile. Throughout the making process everything worked reliably, but during the photoshoot the movements caused several of the delicate connections to loosen or break.

Final test¶

applied to the body¶

model: @ RAÚL BABINES instagram: R a ú l B a b i n e s

Future Improvements¶

For future iterations, I would consider using more robust conductive materials that can better tolerate movement and repeated use, assemble the copper-tape connections directly on location if I choose to work with it again, and select a darker shooting environment, so that the NeoPixels / LEDs stand out more effectively and the light effects become more visible