Neharika Rao SK Convent Father Barre, Sungai Petani Kedah
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ECO-SPINE SMART
A Low-Cost Smart Posture Monitoring System for School Chairs Using Recycled Materials
Innovation Category: Health & Sustainability | Junior Division
Neharika Rao | Nur Adelia Sofea binti Mohd Shahrizam | Nur Dhiya’ Adelia binti Mohd Sufiyan
“Sit Right, Learn Bright.”
Poor sitting posture among school students is a growing health concern that contributes to back pain, neck strain, reduced concentration, and long-term spinal problems including the early onset of scoliosis — an abnormal lateral curvature of the spine that, if left undetected and uncorrected during childhood, may progress into a permanent and debilitating condition. Existing posture correction solutions are often expensive, not eco-friendly, and unsuitable for standard school chairs. Many also rely on disruptive auditory alerts or classroom screen notifications that embarrass students and break the flow of teaching. This paper presents the Eco-Spine Smart, a low-cost, sustainable smart posture monitoring system designed specifically for school chairs using primarily recycled materials.
The Eco-Spine Smart consists of a lumbar and thoracic support cushion constructed from a recycled foam padding, strawboard base and fabric covering sourced from old clothing. The device is secured to any standard school chair using adjustable straps made from repurposed materials. Embedded within the device is a smart electronic module comprising two Force Sensitive Resistor (FSR) pressure sensors, an ESP32 microcontroller, a red LED indicator mounted at the top of the chair backrest, and a portable power supply of four AA batteries connected via an ON/OFF switch. FSR1 is positioned at the upper thoracic level of the backrest (GPIO34) to monitor spinal posture. FSR2 is positioned at the base of the seat cushion (GPIO35) as an occupancy sensor to detect whether a student is physically seated. The system is programmed using MakeCode block-based coding.
A key design principle of Eco-Spine Smart is that posture alerts are delivered through a discreet visual indicator rather than noisy buzzers or public screen displays, preserving student dignity and maintaining classroom focus. The red LED is mounted at the top of the chair backrest visible to both the student (as a personal posture reminder) and to the teacher from across the classroom (as a quiet, non-disruptive indication that a student requires posture guidance). This placement ensures that posture correction can happen naturally and without embarrassment, as the teacher may simply walk over or give a gentle reminder rather than calling out the student’s name on a screen.
The system operates through a two-tier sensor logic designed to eliminate false alarms. FSR2 at the seat base first confirms occupancy. If no student is detected, the system remains inactive. Once a student sits down, the system activates, performs a five-second calibration to record the student’s personal upper Baseline from FSR1, then continuously reads FSR1 every 200 milliseconds. If the reading deviates by more than ±100 units from the baseline indicating slouching, forward lean, or lateral shift associated with scoliosis risk the ESP32 activates the red LED at the top of the chair. The LED deactivates automatically when correct posture is restored. When the student leaves, FSR2 deactivates the system, conserving battery and preventing false alerts.
Prototype testing demonstrated significant improvements: good posture time increased from 45% to 80% (+35%), back discomfort decreased by 40%, neck pain decreased by 35%, and concentration scores improved by 20%. User satisfaction improved from 6.5 to 9.2 out of 10. The LED placement at the top of the chair was particularly well-received, as it allowed teachers to identify posture issues from anywhere in the classroom without disrupting the lesson. Consistent posture correction also reduces the cumulative asymmetric spinal loading associated with scoliosis risk during critical childhood growth years.
The long-term vision for Eco-Spine Smart includes replacing the single red LED with an LED strip running along the top edge of the chair backrest, providing a more visible and aesthetically cohesive indicator for classroom-wide posture monitoring. Additionally, a student-facing LED or small indicator light on the student’s desk is planned, allowing students to self-monitor their posture without needing to turn around. Together, these two indicator points — the chair-top LED (teacher-visible) and the desk LED (student-visible) — create a comprehensive, silent, and non-embarrassing dual-view posture feedback system. By incorporating recycled materials throughout its construction, the Eco-Spine Smart demonstrates that innovative, dignified health technology can be both affordable and environmentally responsible.
Keywords: posture monitoring, scoliosis prevention, occupancy detection, dual FSR sensor, ESP32, MakeCode, chair-top LED indicator, LED strip, desk LED, false alarm prevention, recycled materials, school health, thoracic sensor, sustainable innovation
Students spend an average of 6 to 8 hours daily sitting in school chairs. Without proper back support, many develop a habit of slouching or sitting asymmetrically, which leads to musculoskeletal problems that can persist into adulthood. Of particular concern is the risk of scoliosis, an abnormal lateral curvature of the spine that commonly develops during childhood and adolescence. Prolonged asymmetric spinal loading and lateral flexion during critical growth periods can affect vertebral development, increasing the likelihood of progressive spinal curvature. Without timely correction, the condition may worsen and require medical or surgical intervention.
Current posture correction solutions face three compounding problems. First, they are often expensive and not eco-friendly. Second, many trigger false alarms when chairs are empty. Third, alert mechanisms such as buzzers or classroom screen notifications are disruptive to teaching and embarrassing to students, which discourages consistent use. What is needed is a system that corrects posture silently, preserves student dignity, allows teachers to notice and assist naturally, and is built sustainably at low cost.
• To design a smart posture monitoring device using recycled and low-cost materials.
• To implement a seat-base occupancy sensor (FSR2) that prevents false posture alerts when no student is seated.
• To develop a thoracic posture sensor (FSR1) with personalised baseline calibration and ±100 threshold detection that accurately identifies poor posture.
• To alert students to poor posture through a red LED mounted at the top of the chair backrest visible to the student as a personal reminder and to the teacher as a quiet, non-disruptive classroom indicator without embarrassing the student or disrupting the lesson.
• To reduce the risk factors associated with scoliosis development by promoting consistent upright and symmetrical spinal alignment during school hours.
• To establish a long-term vision for classroom wide posture monitoring through an LED strip at the top of the chair backrest and a student-facing desk LED indicator.
• To promote sustainable innovation by incorporating the 3R principles (Reduce, Reuse, Recycle).
• To evaluate the effectiveness of the device in improving student posture, comfort, and spinal health awareness.
Recycled Materials Used:
• Recycled foam (from old cushion) — padding layer housing the sensors and electronics
• Strawboard / corrugated cardboard (from old boxes) — to hold the electronic parts
• Old fabric, jeans, or t-shirt — outer cover
• Straps from old bags/clothes — adjustable chair fastening
Electronic Components:
• ESP32 microcontroller — central processing unit; programmed using MakeCode block-based coding
• FSR1 (Force Sensitive Resistor, Upper) — positioned at the thoracic level of the backrest; connected to GPIO34; monitors spinal posture
• FSR2 (Force Sensitive Resistor, Lower) — positioned at the base of the seat cushion; connected to GPIO35; acts as an occupancy sensor to detect whether a student is seated
• Red LED (GPIO2) — mounted at the top of the chair backrest; visible to both the student and the teacher; activates when bad posture is detected; deactivates automatically when posture corrects
• 220Ω resistor — current-limiting resistor for the red LED
• Two 10kΩ pull-down resistors — one per FSR sensor for stable ADC readings
• 4 x AA alkaline batteries (~6V total) with ON/OFF switch — powering the ESP32 via the 5V VIN pin; all GND connections are shared
LED Alert Design and Placement:
The red LED is deliberately placed at the top of the chair backrest rather than on a screen or buzzer. This placement serves a dual purpose: the student can see the light glowing above their chair as a personal posture reminder, while the teacher can see it from the front of the classroom without any screen, sound, or announcement. This preserves complete student dignity as no names are called out, no public displays are shown, and no disruptive sounds are made. The teacher may simply walk over quietly or make eye contact to guide the student.
The long-term development plan includes two enhancements. First, replacing the single LED with an LED strip along the top edge of the chair backrest, making the indicator more visible across a full classroom. Second, adding a small LED indicator on the student’s desk, giving the student a direct line-of-sight posture signal without needing to turn around. Together, these create a dual-view alert system: the chair-top LED strip for teacher awareness and the desk LED for student self-monitoring, all without noise, screens, or disruption.
System Operation:
1. Occupancy Check: ESP32 continuously reads FSR2 (GPIO35) at the seat base. If no weight is detected, the system remains in standby and the red LED stays off. No false alarms on empty chairs.
2. Activation: When FSR2 detects a seated student, the posture monitoring function activates.
3. Calibration: System waits 5 seconds for the student to settle, then reads FSR1 (GPIO34) and stores this as upper Baseline — the personalised reference for correct posture.
4. Continuous Monitoring: ESP32 reads FSR1 every 200 milliseconds and compares the current reading to upper Baseline.
5. Good Posture: If |upper Value – upper Baseline| < 100, the red LED at the top of the chair remains off. Display shows “GOOD POSTURE”.
6. Bad Posture Alert: If deviation ≥ 100, the red LED at the chair top activates (GPIO2 HIGH). Both the student and the teacher can see it. Display shows “BAD POSTURE!”.
7. Auto-Reset: When posture corrects, the LED deactivates automatically.
8. Deactivation: When FSR2 no longer detects occupancy, the system returns to standby, conserving battery.
Prototype testing with student volunteers demonstrated significant improvements across all measured outcomes. Good posture time increased from 45% to 80% (+35%). Back discomfort dropped by 40% and neck pain by 35%. Concentration scores improved by 20%. Overall user satisfaction rose from 6.5/10 to 9.2/10. The red LED placement at the top of the chair backrest was specifically highlighted by both students and teachers as an effective and respectful alert mechanism students felt the red light was a personal reminder rather than a public announcement, and teachers appreciated being able to identify posture issues from the front of the classroom without interrupting the lesson.
The occupancy detection function of FSR2 successfully eliminated false alerts when chairs were unoccupied, making the system significantly more accurate. The personalised baseline calibration adapted the threshold to each individual student, ensuring consistent accuracy across different body types and heights. The thoracic sensor placement of FSR1 effectively detected both forward slouching and lateral spinal shift, the postures most associated with scoliosis risk enabling early and consistent correction before these habits become permanent.
The Eco-Spine Smart successfully demonstrates that a functional, accurate, and dignified smart posture monitoring device can be built primarily from recycled materials at minimal cost. Its two-tier sensor logic FSR2 at the seat base for occupancy detection and FSR1 at the thoracic level for posture monitoring, eliminates false alarms and ensures accurate, personalised detection. The red LED mounted at the top of the chair backrest serves as a silent, non-embarrassing dual-view alert: visible to the student as a personal reminder and to the teacher as a quiet classroom indicator, without any disruptive noise or public screen display.
The long-term vision , an LED strip along the chair top for enhanced teacher visibility and a desk-mounted LED for student self-monitoring, will further strengthen the system’s effectiveness while maintaining its core principle of dignity-first, disruption-free posture correction. Future development may also include wireless teacher notifications and a mobile application for long-term posture trend tracking and scoliosis risk indicators. The Eco-Spine Smart is a compelling model for green, student-centred health innovation in schools.
The Eco-Spine Smart project directly supports the following United Nations Sustainable Development Goals:
SDG 3 — Good Health and Well-Being
By monitoring thoracic posture in real time and alerting both the student and teacher through a discreet LED at the top of the chair, the device helps prevent musculoskeletal disorders, reduces back and neck pain, and promotes healthy spinal habits from a young age. Consistent posture correction reduces the cumulative asymmetric spinal loading that drives scoliosis development during childhood growth years, contributing to SDG 3’s target of ensuring healthy lives and wellbeing for all.
SDG 4 — Quality Education
By improving physical comfort and replacing disruptive alert mechanisms with a silent LED indicator, Eco-Spine Smart creates better conditions for learning without interrupting lessons. Testing showed a 20% improvement in concentration scores. The dignity-first design means students are more likely to engage with and consistently use the device, supporting SDG 4’s aim of inclusive and equitable quality education for all.
SDG 12 — Responsible Consumption and Production
Built almost entirely from recycled and repurposed materials — cardboard, foam, old fabric, and bag straps — the project embodies the 3R principles of Reduce, Reuse, and Recycle. This aligns with SDG 12’s call for sustainable consumption and production, showing that effective health technology does not need to rely on new raw materials.
SDG 13 — Climate Action
By diverting materials from landfill, avoiding new manufacturing, and instilling eco-conscious values in students through the innovation process itself, Eco-Spine Smart contributes to reducing waste and carbon footprint, supporting SDG 13’s call for urgent climate action through education and sustainable practices.
In summary, the Eco-Spine Smart is not merely a posture correction device — it is a sustainable, dignity-first innovation that simultaneously addresses back pain, scoliosis risk, student concentration, false alarm prevention, and responsible material use, while delivering a silent, respectful classroom posture monitoring experience for both students and teachers.
Eco-Spine Smart | “Sit Right, Learn Bright.” | Innovation Project | Junior Division
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