CoolShoe

THE WORLD'S FIRST SELF-POWERED COOLING SHOE

TEC · WRISTIFY LOGIC PIEZO + SOLAR SINGAPORE HEAT
01 / 10

THE PROBLEM

Singapore is one of the
hottest cities on Earth.

35°C
NEW NORMAL BY 2050
Singapore's 3rd National Climate Change Study projection
+250%
HEAT ILLNESS RISK
Per 1°C temperature rise. Per SGH study, 2026.
440K
OUTDOOR WORKERS
Construction, marine, process sectors. Most exposed daily.
02 / 10

EXISTING SOLUTIONS

Every current solution
has a fatal flaw.

Handheld fan
Moves hot humid air. At 90% humidity sweat can't evaporate — fan adds zero benefit.
MOVES HOT AIR
Portable aircon
Needs power outlet. Weighs 15 kg. Exhausts hot air from the back. Stationary.
NOT PORTABLE
Cooling vest
Ice packs last 90 min then become dead weight. Limits movement. Impractical all day.
SHORT RUNTIME
Misting tent
Fixed location. Workers must stop and walk to it. Mist disperses in wind outdoors.
STATIONARY
Umbrella / shade
Blocks solar radiation but not radiant ground heat or humidity. No active cooling.
PASSIVE ONLY
Neck fan / wristband
Gets in the way of gloves and tools. Visible gadget. Short runtime. Not for workers.
WRONG PLACEMENT
03 / 10

THE SOLUTION

A shoe that
cools you as you walk.

TEC Peltier tile in tongue flap · Wristify pulse logic · dorsalis pedis artery · completely hidden under laces.

🧊
Direct skin cooling
Cold face of TEC tile contacts the dorsalis pedis artery through the tongue.
🧠
Wristify logic
MIT-proven 0.1°C/s pulse waveform makes brain perceive 3–5°C whole-body cooling.
👟
Invisible design
9 mm tongue — same as a normal shoe. Hidden under laces. Looks completely standard.
🔇
Zero noise
Solid state TEC — no fan, no motor, no moving parts. Completely silent operation.
04 / 10

HOW IT WORKS

Six steps from heel to cool.

01
Heel strikes
1.2–1.5× body weight compresses PVDF piezo film in midsole.
→
02
Voltage spike
Deformed crystals generate 20–60V AC spike per step.
→
03
Boost + store
MPPT converter rectifies to 3.7V DC, charges 150mAh buffer.
→
04
MCU decides
ARM chip monitors skin temp. Fires TEC when foot ≥35°C.
→
05
TEC pulses
3s on / 5s off Wristify waveform hits dorsalis pedis artery.
→
06
You feel cool
Brain perceives 3–5°C cooler body. No charger. No effort.
MIT Wristify research (2013): Heating or cooling any nerve-dense body part at ≥0.1°C/s makes the entire body feel several degrees warmer or cooler. The foot dorsum — like the wrist — has the dorsalis pedis artery just 1–2 mm below the skin. Same effect. Better placement for workers who need their hands free.
05 / 10

POWER SYSTEM

Never needs charging.

Piezo harvest + solar supplement · self-sustaining loop

PRIMARY
⚡
Piezoelectric harvest
~30 mW
14 PVDF film layers in midsole. Every step generates power. Works indoors, outdoors, rain.
SUPPLEMENT
☀
Solar (perovskite film)
~150–400 mW
Thin-film on tongue face. Works in direct sun, diffuse light, even overcast SG days.
🔋
TEC needs (pulsed)
~15 mW
Wristify duty cycle: 3s on / 5s off. Average draw is tiny. Harvest vastly exceeds need.
Harvest (8,000 steps/day)
~240 mWh
TEC consumption (4h cooling)
~72 mWh
Net surplus stored
~168 mWh
06 / 10

DESIGN SPECIFICATIONS

Every component. Every number.

TEC MODULE
Tile size30 × 30 mm
Thickness3.4 mm
Cold face temp18–22°C
Power (pulsed avg)3–4 W
Noise0 dB
Weight4 g per tile
BATTERY + MCU
Buffer cell150 mAh flat LiPo
Standstill reserve~45 min
Charge portUSB-C (emergency)
MCU chipARM Cortex-M0+
Trigger temp≥35°C skin
Pulse waveform0.1°C/s · MIT proven
POWER HARVEST
Piezo materialPVDF film
Film layers14 per shoe
Output (walking)~30 mW
Solar materialPerovskite thin-film
Solar output (sun)150–400 mW
Converter ICLTC3588 MPPT
SHOE CONSTRUCTION
Tongue depth9 mm total
Module weight (pair)28 g
WaterproofingIPX4
UpperMesh knit + TPU
Module removableYes · tongue unzips
Est. retailSGD 180–240
07 / 10

THERMAL MANAGEMENT

The shoe = a fanless mini-PC.
Same thermal stack. 3W workload.

COOLSHOE TONGUE
EQUIVALENT
CPU / LAPTOP
Outer mesh fabric · 1mm
= heat source
CPU / processor chip
Thermal pad · 0.3mm
= interface
Thermal paste
TEC Peltier tile · 3.4mm
THE ENGINE
Peltier (same tech)
Graphite spreader · 0.2mm
= spreader
Aluminium heatsink base
Flat LiPo + MCU · 2.3mm
= controller
Motherboard + power
Passive tongue-edge vent
= exhaust
Laptop exhaust vent
Foot skin (dorsalis pedis)
= output
Screen / computation
08 / 10

TARGET USERS

Built for Singapore's heat warriors.

🏗
Construction workers
8–10 h exposed. Mostly migrants. 440K workers at risk. Heat illness risk +250% per 1°C rise.
PRIMARY
🛵
Delivery riders
Income tied to hours. Can't stop to cool down. Hands need to be free at all times.
PRIMARY
🍜
Hawker vendors
Cooking heat + ambient heat in semi-outdoor environment. Standing all day. No AC.
SECONDARY
🚶
Commuters + elderly
Daily outdoor exposure. Elderly have reduced heat tolerance. Higher stroke risk.
SECONDARY
RETAIL CONSUMER
SGD 180–240
B2B FLEET (PER PAIR)
SGD 140–180
MODULE ONLY (RETROFIT)
SGD 60–90
TARGET MARKET SG
440K+ workers
09 / 10

THE FUTURE OF PERSONAL COOLING

Walk cool.
Stay cool.
TEC · SILENT WRISTIFY LOGIC PIEZO + SOLAR 9MM TONGUE 0 dB NO CHARGER 28 G SGD 180–240

COOLSHOE · PROTOTYPE v3.0 · SINGAPORE 2025

10 / 10