Nanotechnology works at roughly 1 to 100 nanometres. A nanometre is one billionth of a metre. A sheet of paper is about 100,000 nanometres thick.
A ladder of sizes helps:
- A sheet of graphene: one atom thick, a fraction of a nanometre.
- A lipid nanoparticle in an mRNA vaccine: roughly 100 nanometres, about the size of a virus.
- A neuron's cell body: thousands to tens of thousands of nanometres across.
- A sheet of paper: about 100,000 nanometres.
- A 2016 neural dust sensor: about 3 millimetres long, or 3,000,000 nanometres.
The last line is the point most often missed. Most of what is called nanotechnology in brain research is a device of ordinary, visible size built from nanomaterials: graphene electrodes, nanowire mesh, a millimetre-scale sensor. The parts that are truly nanoscale are particles, and a particle on its own cannot compute, store or transmit anything.
What nanoscale technology does today, on the record:
- Carries medicines and genetic instructions into cells, as in mRNA vaccines and other approved nanomedicines.
- Makes electrodes thinner, softer or transparent, as in transparent brain-computer interfaces and graphene arrays now being tested in people during surgery.
- Converts energy sent from outside the body into a local effect, in laboratories and animals: magnetoelectric nanoparticles respond to a magnetic field, and in optogenetics upconversion nanoparticles turn near-infrared light into visible light. In both cases the power and the instruction come from equipment outside the body.
What is only proposed: nanoscale robots that travel through the bloodstream, position themselves among brain cells and link the brain to a network. That idea has been published as a proposal (see What is a brain/cloud interface?). Nothing of the kind has been built.
- Nanoscale is roughly 1 to 100 nanometres; a sheet of paper is about 100,000 nanometres thick (U.S. National Nanotechnology Initiative)
- Neural dust motes demonstrated in 2016 were about 3 millimetres long (UC Berkeley)
- Magnetoelectric nanoparticles and upconversion nanoparticles act only when driven by an external magnetic field or light source
- Brain-linked nanorobots exist only as a published proposal (Frontiers in Neuroscience, 2019)
Open questions
- Size alone does not set a limit on what future devices could do. This concept describes what is on the record now.
References
- Just How Small Is Nano? — U.S. National Nanotechnology Initiative
- Sprinkling of neural dust opens door to electroceuticals — Berkeley News (2016)
- Near-infrared deep brain stimulation via upconversion nanoparticles — RIKEN (2018)
- Did anyone try to build a way in without surgery?
Each source is cited for the measurement or result it reports.
Not independently verified
This concept summarises published sizes and demonstrated capabilities. It does not predict what future devices will or will not do.
Topics: Nanotechnology · Technology