BioCap product render — a white 3D-printed milk cap with conductivity probe
Patent Pending 64/144,568
Download Patent Drawings

BioCap

Know Before You Pour.

A milk cap that detects if your milk is spoiled before you pour.

Input from researchers, alumni, and professors at the following institutions.

MIT

University of Chicago

Cornell University

Wharton · UPenn

Baxter

The Problem


We throw out good milk every day because we can't be sure if it's spoiled or not.

COVID & Illness Impact

Millions lost their sense of smell due to COVID-19 — making smell-based freshness checks unreliable for a large portion of the population.

Issues of Food Poisoning

Millions get sick every year from contaminated or spoiled food.

Sources: USDA Economic Research Service; peer-reviewed food science literature; survey of 20+ households.

~$2B in household dairy wasted annually in the US
78% rely on smell alone to check milk freshness
91% unsatisfied with relying only on expiration dates

Printed dates are a rough estimate — they never actually measure the milk in your carton.

Expiration Date


Printed dates estimate freshness — they do not measure the milk itself.

Are people happy with using just the expiration date?

91% Unsatisfied

with relying only on expiration dates

BioCap provides a real-time freshness check — not a printed-date guess.

How BioCap Works

Screw it on. Get a reading. Know before you pour — in seconds, not guesses.


Step 1

Bacteria produce acidic byproducts

As milk spoils, bacterial metabolism produces acids such as lactic acid, increasing mobile ions in the liquid.

Step 2

Conductivity rises

More free ions increase electrical conductivity, giving the system a measurable signal tied to spoilage.

Step 3

BioCap compares delta from baseline

The system establishes a fresh baseline, then measures delta conductivity to account for natural variation.

Step 4

Thresholds classify the sample

Fresh is below 150 µS/cm, borderline is 150–400 µS/cm, and spoiled is above 400 µS/cm.

See BioCap in action

Prototype demo — real conductivity sensing on a live sample.

Conductivity Simulator

Adjust the slider to change delta conductivity in microSiemens per centimeter. The cap compares that value to a fresh baseline and classifies the milk.

Fresh

Sample looks stable.

The delta conductivity is below 150 µS/cm, suggesting minimal bacterial activity.

Baseline 4850 µS/cm
Current 4920 µS/cm
Confidence 95%

Why Conductivity

We evaluated 4 approaches before selecting conductivity sensing as our solution.

Container Closure with Conductivity-Based Liquid Freshness Estimation

U.S. Provisional Patent Application No. 64/144,568 · Filed Aug 30, 2026

Patent-pending smart closure that quantifies spoilage by detecting conductivity shifts caused by increasing ionic concentration from metabolic byproducts such as lactic acid. It establishes a container-specific baseline, then algorithmically compares subsequent measurements to classify freshness degradation.

BioCap patent drawing — Figure 1
Figure 1
BioCap patent drawing — Figure 2
Figure 2
Approach Accuracy Cost Portability Selected
pH / Acid Strip Medium $$ High
Color / Visual Sensor Low $$$ Medium
Conductivity Sensing High $$ High

Why conductivity?

As bacteria metabolize lactose they produce acids, releasing more mobile ions and measurably raising electrical conductivity — a precise, physics-based, non-invasive spoilage signal.

Market Alternatives


When the date isn't enough, most people fall back on smell — and that has its own limits.

Smell Test


Smell is subjective and unreliable — especially for anyone who has lost their sense of smell.

How do most households check milk today?

78% Smell alone

rely on smell to judge freshness

BioCap measures what is actually in the milk — conductivity, not guesswork.

Design & Build

The BioCap body was designed around a cap shape, clean grip texture, handle, and centered probe channel.

Product Render
BioCap product render showing ribbed grip texture and probe
CAD Design Process
Fusion 360 CAD design process for BioCap
Design Focus: Printable Geometry User-Friendly Silhouette Protected Electronics Stable Milk-Contact Probe Position
Exploded View
BioCap component exploded view diagram
Firmware
BioCap Arduino firmware code
LED Indicator State LED provides visual feedback on power, status, and activity.
Arduino Nano The brain of the system handles data processing and sensor communication.
Battery 9V battery powers the entire system for long-term use.
Conductivity Sensor High-sensitivity sensor detects ionic changes to measure freshness.
3D Printed Body & Cap Custom 3D-printed enclosure keeps all components secure and protected.

Built on real research.

Guided by leading scientists and mentors — not built in a vacuum.

Research and Guidance That Shaped BioCap — presentation slide with Professor Rabinow, university credentials, research collage, and quote
BioCap team receiving first place at CIJE Innovation Day

First place at CIJE Innovation Day.

BioCap took first place at CIJE Innovation Day.

Impact

Real impact. Measurable change.

01
Less Waste

30–40%

of milk discarded before it truly spoils — BioCap can recover that.

02
Home + Retail

$2B+

$2B+ in US dairy wasted annually — a massive market opportunity.

03
Safer Choices

91%

of surveyed users want a dedicated milk freshness device.

Survey Results

88%

Would use the cap daily

94%

Found LED readout intuitive

"A small cap. A big difference."

Thank You

BioCap — Know Before You Pour.