Collect and Observe Fingerprints

This simple experiment allows students to collect and observe their unique fingerprints using only pencil lead, tape, and paper. It highlights the individuality of fingerprints and how they can be used for identification.

1. Draw a 2.5 cm (1 inch) square on a sheet of paper and shade it in heavily with a pencil until it is very dark.
2. Roll your finger across the shaded square from tip to first knuckle to coat it with graphite.
3. Press a piece of clear tape gently onto your finger without smudging the print.
4. Peel off the tape and place it sticky side down on the paper.
5. Observe the ridges and patterns that make up your fingerprint.

Unique As Your Fingerprint at Home STEM Experiment - MilliporeSigma:

📄 Unveiling the Unique: A fingerprint experiment to look at the intricate patterns of identity - Small Step for STEM: https://www.smallstepforstem.com/unveiling-the-unique-fingerprints/

• Compare fingerprints between classmates and note differences in patterns (loops, whorls, arches).
• Try different fingers from the same hand to see if they all have the same type of print.
• Collect fingerprints on index cards and challenge students to match them as a detective exercise.

• Avoid pressing too hard with the pencil to prevent breaking it or tearing the paper.
• Wash hands after the activity to remove graphite.
• Keep tape away from hair and clothing to avoid tangling or damage.
• Destroy fingerprints after the activity to protect privacy.

• Why are fingerprints unique? (They form through complex genetic and developmental factors that make each person’s ridges different.)
• Do fingerprints ever change? (No—if skin is cut or scraped, the same pattern grows back after healing.)
• How are fingerprints used in real life? (Forensics, personal identification, biometric security systems.)
• Why might some fingerprints appear clearer than others in this activity? (Differences in graphite coverage, finger pressure, or tape placement.)