MiniBank: Smart Saving for Kids

This project explores a smart mini bank system that goes beyond traditional saving to teach children how to save with purpose. While conventional piggy banks and school-led saving schemes encourage putting money aside, they rarely guide children on how to save strategically toward a goal. This project seeks to bridge that gap.

Smart Piggy Bank Concept Internal Mechanism View

Inspired by how children learn arithmetic through everyday actions like adding coins or calculating change, this concept introduces structured, goal-based saving through interaction. The piggy bank functions as a mini banking system, internally organizing deposited coins to make savings visible and purposeful.

I am currently working with two conceptual approaches. The first is a goal-based model where a child sets a specific savings target and receives weekly guidance on how much to save. The second draws from the simplified 50–30–20 principle, where only a portion of the saved amount is accessible, encouraging discipline and delayed gratification. By combining saving with intention and planning, the piggy bank becomes an active learning tool rather than a passive container.

Concept & Rationale

Children are often told to save money, but rarely taught how to save wisely. Many accumulate coins without a clear purpose, leading to impulsive spending once the money is accessed. This pattern often continues into adulthood. I observed similar contrasts among colleagues on the same payroll—some struggled before month-end, while others managed comfortably. This raised a key question: why does saving feel intuitive for some, but not for others?

This reflection led to the idea of teaching children not just to save, but to save with intention.

The Smart Mini Bank introduces goal-oriented saving, where a child sets a specific target (with parental guidance) and works toward it through consistent contributions and delayed access to funds. Saving becomes a structured and intentional process rather than simple accumulation.

Smart Piggy Bank Learning System

Through this process, the child learns:

  • Restraint and patience
  • Delayed gratification
  • Foundational financial awareness
  • An understanding of planning over impulsive spending

To reinforce positive saving behavior, the Smart Mini Bank rewards the child upon successful completion of a goal by adding a small amount of interest to the saved total, introducing simplified real-world financial principles in an age-appropriate manner. Parents act as facilitators rather than enforcers, guiding reflection and discussion instead of merely controlling access to money.

At its core, this project reimagines the traditional piggy bank as a Smart Mini Bank, an interactive system that encourages purposeful saving and helps children develop a healthy, intentional relationship with money from an early age.


Initial concept model on SketchUp


Preliminary Diameter and Material Study for Coin Identification System Design

Since my final project involves designing a coin identification system that detects denomination and updates a running total, it was necessary to analyze whether Indian coin denominations are dimensionally consistent across different series. Accurate value computation depends on reliable physical identification; therefore, I first examined variations in diameter and material among commonly circulated coins.

Comparison across models

₹1 Coin Series Comparison

Series Diameter Material Type
1988 Stainless Series 25 mm Stainless Steel Single
2004 Unity 25 mm Stainless Steel Single
2007 Hasta Mudra 25 mm Stainless Steel Single
2011 Rupee Symbol 21.93 mm Stainless Steel Single
2019 Grain Series 20 mm Stainless Steel Single

₹2 Coin Series Comparison

Series Diameter Material Type
1988 Series 26 mm Copper-Nickel Single
2004 Unity 26.75 mm Stainless Steel Single
2007 Hasta Mudra 27 mm Stainless Steel Single
2011 Rupee Symbol 25 mm Stainless Steel Single
2019 Grain Series 23 mm Stainless Steel Single

₹5 Coin Series Comparison

Series Diameter Material Type
1988 Series 23 mm Copper-Nickel Single
2004 Unity 23 mm Stainless Steel Single
2007 Common (Steel) 23 mm Stainless Steel Single
2007 Common (Nickel-Brass) 23 mm Nickel-Brass Single
2011 Rupee Symbol 23 mm Nickel-Brass Single
2019 Grain Series 25 mm Nickel-Brass Single

₹10 Coin Series Comparison

Series Diameter Material Type
2004 Unity 27 mm Center: Copper-Nickel
Ring: Aluminium-Bronze
Bimetallic
2007 Common 27 mm Center: Copper-Nickel
Ring: Aluminium-Bronze
Bimetallic
2011 Rupee Symbol 27 mm Center: Copper-Nickel
Ring: Aluminium-Bronze
Bimetallic
2019 Grain Series 27 mm Center: Copper-Nickel
Ring: Aluminium-Bronze
Bimetallic

₹20 Coin Series Comparison

Series Diameter Material Type
2019 Grain Series 27 mm Center: Nickel-Brass
Ring: Nickel Silver
Bimetallic

Final Comparison Summary

Denomination No. of Varieties Diameter Range Materials Used
₹1 5 20–25 mm Stainless Steel
₹2 5 23–27 mm Copper-Nickel, Stainless Steel
₹5 6 23–25 mm Copper-Nickel, Stainless Steel, Nickel-Brass
₹10 4 27 mm Bimetallic (Cu-Ni + Al-Bronze)
₹20 1 27 mm Bimetallic (Ni-Brass + Ni-Silver)

Design Implications for the Identification System

  • Detection thresholds must account for diameter ranges, not a single nominal value.
  • Overlapping size differences between denominations must be carefully analyzed to avoid misclassification.
  • Material consistency (e.g., stainless steel vs. bimetallic structure) may support future sensor-based differentiation.
  • System calibration should prioritize maximum and minimum diameter boundaries within each denomination.
  • Overall, this study defines the diameter ranges and material variations that must be considered while designing the coin identification mechanism.


    Materials

    Qty Description Price Link
    Material one 22.00 $ https://amazon.com/testoe Order many
    Material two 22.00 $ https://amazon.com/testoe
    Material three 22.00 $ https://amazon.com/testoe
    Material four 22.00 $ https://amazon.com/testoe