Biosensor miniaturization is the engineering effort to shrink a biosensor’s sensing element, electronics, and power source so the device can be worn or implanted with less burden on the user. In diabetes monitoring, it has transformed the continuous glucose monitor (CGM) from a multi-part system into a single disposable wearable and is now moving glucose sensing into shallower layers of the skin.
This article covers the techniques behind smaller biosensors, what they have delivered in diabetes devices so far, and what they mean for teams building products around them. For how each sensing method works and which devices are on the market, see our guide to CGM technology.
Biosensor Miniaturization Techniques
Biosensor miniaturization draws on advances in materials, fluid handling, and electronics. Four areas account for most of the progress in glucose biosensors.
Nanomaterials
Nanomaterials let a smaller electrode do the work of a larger one. Carbon nanotubes and graphene add surface area and electrical conductivity, which raises the signal a sensor can produce from a small sample. A 2024 review notes that graphene “offers an extensive surface area and excellent conductivity”, while carbon quantum dots are used mainly for their optical properties and biocompatibility (Ambaye et al., Frontiers in Sensors, 2024).
Microfluidics
Microfluidics moves and measures very small volumes of fluid inside a wearable device. A review of microfluidics for wearable biosensors cites “low volumes, high sensitivity, rapid processing” as its main advantages (Padash et al., Sensors, 2020). This matters most for sensors that sample sweat or interstitial fluid at the skin surface.
Flexible and stretchable electronics
Flexible electronics allow a sensor to bend with the skin rather than sit on it as a rigid block. A 2022 review of skin-like wearable sensors found that flexibility and stretchability “affect the accuracy of the signal and adhesion to the skin” (Huang et al., Sensors and Diagnostics, 2022).
Alternative sensing chemistries
Most glucose biosensors rely on an enzyme, glucose oxidase. Enzyme-based sensors are well proven, but the enzyme layer is “easily affected by temperature, pH changes and humidity” (Johnston et al., Frontiers in Bioengineering and Biotechnology, 2021). That limits how long a small sensor stays stable.
Researchers are studying enzyme-free alternatives, including nanomaterial electrodes and optical methods such as surface plasmon resonance and fluorescence (Adeel et al., Biosensors and Bioelectronics, 2020). These approaches promise better stability, not proven higher sensitivity. A 2025 review states that traditional enzyme-based sensors still exhibit superior selectivity and high sensitivity (Yang et al., Coatings, 2025), while another reports that reliability, biocompatibility, and calibration-free operation remain unresolved for enzyme-free sensors (ChemistryOpen, 2025).
Aptamer-based sensors are at an earlier stage. A 2026 review reports that their working lifetimes in the body “remain limited to hours rather than days” (Lee et al., Soft Science, 2026).
What Biosensor Miniaturization Has Delivered in Diabetes Devices
Biosensor miniaturization has already changed the CGMs that patients wear. The table shows what each step made possible and where it stands today.
| What miniaturization enabled | Example | Status |
|---|---|---|
| Sensor and transmitter in one wearable | Dexcom G7: 60% smaller than a prior-generation Dexcom CGM | Marketed |
| A sensor the size of two stacked US pennies | FreeStyle Libre 3, described by Abbott as the smallest and thinnest among patient-applied sensors | Marketed (now as Libre 3 Plus) |
| A disposable, all-in-one CGM | Simplera: half the size of previous Medtronic CGMs | Marketed |
| Two analytes in one sensor | Libre Duo 10 Day: glucose and ketones | FDA authorized August 2026; US launch planned |
| Sensing in the upper skin layer, no introducer needle | Biolinq Shine: microsensor array in the papillary dermis | FDA authorized |
| A further size reduction | Dexcom G8: 50% smaller than the G7 | Announced, not cleared |
| A self-powered implanted sensor | Senseonics Gemini | In pivotal trial |
Smaller is not the only goal. Sensor makers are also extending wear time, and the two are in tension: a smaller device has less room for adhesive, battery, and enzyme. Dexcom notes that about 26% of its G7 15 Day sensors may not last the full 15 days (Dexcom).
Why Biosensor Miniaturization Matters to Users
Biosensor miniaturization matters to users because the physical device is a documented barrier to CGM use. A 2024 study of CGM adoption lists sensor adhesion and skin problems at insertion sites as physical barriers, alongside body image and stigma (Zoccarato et al., BMC Health Services Research, 2024). A smaller, flatter sensor is the direct engineering response to those barriers.
The practical gains are easy to list:
- A lower-profile sensor is harder to knock off and easier to wear under clothing.
- An all-in-one disposable eliminates the need for a separate transmitter to charge, pair, and reattach.
- A longer-lasting sensor means fewer insertions and less waste.
Smaller sensors also carry more weight in treatment. CGM data now drives automated insulin delivery, and a meta-analysis of 40 studies found that these systems increased time in the target glucose range by 9.62 percentage points over 24 hours (Bekiari et al., BMJ, 2018).
Where Biosensor Miniaturization Is Heading
Biosensor miniaturization is heading in three directions, as already evident in authorized or announced products.
- More analytes in the same footprint. The Libre Duo 10 Day adds ketones to a glucose sensor. Dexcom lists multi-analyte sensing in its development pipeline.
- Shallower placement. Microsensor arrays such as the Biolinq Shine sit in the upper layer of the skin and need no introducer needle. The Shine reports glucose ranges by color, not numeric values.
- Less hardware on the body. The announced Dexcom G8 is half the size of the G7, and Senseonics is developing implanted sensors that carry their own power and, later, their own Bluetooth radio.
Fully noninvasive glucose sensing is a separate question. No noninvasive glucose monitor has FDA authorization, and the status of optical, radio frequency, sweat, and tear-based methods is covered in our CGM technology guide.
What Biosensor Miniaturization Means for Biosensor Product Development
Biosensor miniaturization shifts work from the device to the software around it. As the on-body hardware shrinks, the companion app and cloud platform take on more of the product.
| As the sensor gets smaller | The software has to |
|---|---|
| The battery and radio budget shrink | Manage Bluetooth connections efficiently and backfill readings after a dropped link |
| The separate receiver and display disappear | Carry the full user experience in the mobile app, including alerts |
| Sensors last longer but can end early | Track sessions, warn before expiry, and handle early sensor failure |
| A second analyte is added | Model, display, and alert on a new data stream, with its own verification evidence |
| Sensor generations turn over quickly | Support more than one sensor model and migrate users between them |
Regulatory work grows with connectivity. A connected biosensor is reviewed as a system, so developers have to show analytical performance, cybersecurity, data integrity, and software reliability together. Addressing those requirements early reduces rework. See SaMD regulatory pathways, diabetes tech interoperability, and Bluetooth Low Energy in wearables for detail.
Sequenex develops the companion apps and cloud software around biosensors and CGMs, engineered under the rigor of our ISO 13485-certified QMS. If you are developing a biosensor product, see our biosensor and CGM software development services.
Frequently Asked Questions About Biosensor Miniaturization
What is biosensor miniaturization?
Biosensor miniaturization is the process of reducing the size of a biosensor’s sensing element, electronics, and power source while maintaining reliable measurements. It relies on nanomaterials, microfluidics, flexible electronics, and low-power wireless components.
How small are current CGM sensors?
Current CGM sensors are roughly the size of a large coin. The Simplera sensor measures about 28.7 by 28.7 by 4.8 mm (Simplera user guide), and Abbott describes the FreeStyle Libre 3 as the size of two stacked US pennies.
Are non-enzymatic glucose sensors used in CGMs today?
Non-enzymatic glucose sensors are not used in marketed CGMs. Wearable CGMs use the enzyme glucose oxidase, and the implanted Eversense sensor uses fluorescence. Enzyme-free sensors remain in research, with reliability and biocompatibility still unresolved.
Is there a CGM that measures more than glucose?
The Abbott Libre Duo 10 Day measures glucose and ketones in one sensor. The FDA authorized it in August 2026 as the first wearable in the United States that continuously monitors ketone levels.
