Category Archives: electronics

An electronic eye on the children


Cover of VN, Aug. 2, 2014

Article in Vrij Nederland (in Dutch), d. Aug. 2, by Marjolein van Trigt about Child Tracking. In there, Wouter Serdijn explains the possibilities, impossibilities and implications of an implantable RFID child tracker. Click here:

IEEE CASS Summer School on Wearable and Implantable Medical Devices; intro of my talk on low-power low-voltage circuit design on YouTube

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Published on Jul 10, 2013

Una pequeña descripción de su investigación, en circuitos de bajo consumo y miniaturización de los mismos. Su descripción aqui

Injectable Electronics: dawn of a new era in electroceuticals?

Injectable electronics still need to become smaller

Frequent readers of this weblog may still remember a previous post, entitled “And the paralyzed will walk again“. This phrase comes from a Discovery Channel movie/documentary, called “2057: the body”, in which it is predicted that by the year 2057 you will be able to survive a three story fall and even be able to walk again as there will be tiny microstimulators attached to your muscles, which can be injected.

Injectable electronics, how fascinating would that be! No more lengthy surgeries, during which only a single, bulky device is implanted, but rather a procedure that takes less than a couple of minutes, during which multiple micro-stimulators are inserted via a seringe. Once done, these stimulators will form a wireless network and will provide the motory neural pathway with well-timed electric stimuli necessary to evoke the correct contraction of the multiple muscles involved in a delicate movement or even seemingly simple posture control.

But how feasible is this idea of injectable electronics? If you search for the term injectable electronics, you will most likely find a lot of references to the work of John Rogers, professor at the University of Illinois in the US, who built “an electronic LED device so tiny it can be injected into delicate tissue, such as in the brain, without harming it“.
Other links that can be found refer to work done on silk implants or even magnesium implants that are either stretchable or can easily dissolve into the body once the good work has been done.

I personally believe that we only can create injectable electronic devices if they have at least some intelligence in them. For this, the good old silicon would be an excellent candidate. Silicon is a nice and friendly biocompatible material, can be made bendable (by thinning the substrate) or stretchable (by removing the substrate altogether at some points). And what’s more, silicon can accommodate stimulation circuitry, sensors, signal processing, communication electronics, antennas, battery foils, all the good stuff needed to make a good injectable.

Of course, in order not to damage the tissue that the electronic device is injected in, it needs to be small, i.e., thin and narrow. It is however allowed to make it long, e.g., a couple of millimeters up to one or two centimeters. These unconventional dimensions raise very exciting technological challenges, such as:

  • how can we create electronic integrated circuits (ICs) that are merely one-dimensional, i.e., are not wider than one, maximally two, bondpads?
  • how can we transfer information and energy to an implant that has virtually no area?
  • what kind of material should we use for the antenna and electrodes?
  • will a Li-Ion battery foil have enough capacity to provide successful stimulation of the tissue, or should we refrain from using batteries altogether?

There obviously is still a lot to do. Exciting stimes ahead, if you ask me.


A new name, but Biomedical Electronic remains

Biomedical Electronics Lab

Dear Reader,

The Biomedical Electronics Group underwent a small name change. From now onwards, the group is called “The Biomedical Electronics Laboratory”.

Its mission is “to provide the technology for the successful monitoring, diagnosis and treatment of cortical, neural, cardiac and muscular disorders by means of electroceuticals.”

To this end it conducts research on, provides education in and helps creating new businesses in neuroprosthetics, biosignal conditioning / detection, transcutaneous wireless communication, power management, energy harvesting and bioinspired circuits and systems.


At the annual general assembly of the Delft Research Center on ICT (DIRECT), we proudly presented one of TU Delft’s faculty flagship projects “Beethoven”. Beethoven is a technology-driven research project on electroceuticals that aims at the design of a flexible brain … Continue reading

Neurostimulation causes nerves cells to grow back and allows paralyzed to walk again

Article from De Volkskrant, dd. Oct. 27, 2012, entitled "Paralyzed walks again"

Article from De Volkskrant, dd. Oct. 27, 2012, entitled “Paralyzed walks again”

Eddy was damn right when after the disk in his spinal cord was removed by the neurosurgeon and he lost almost all the feeling in one of his legs due to the acute hernia. By means of transcutaneous stimulation of his foot and leg he was able to regain feeling and control over his muscles  and walk again. The method was not proven scientifically yet, but obviously worked, as we witnessed from closeby. Now the scientific proof is there.

Exciting times ahead, if you ask me.


Article in “De Telegraaf”, September 29, 2012 (in Dutch)

Artikel Telegraaf


First implantation of a vestibular implant

Today it was reported in ‘De Volkskrant’ that doctors of Maastricht University Medical Center have succeeded in, for the first time ever, implanting an artificial balance organ, a vestibular implant, in two patients. A vestibular implant is more or less a cochlear implant that relays information on orientation and accelleration onto the hair cells in the vestibula, the small organ attached to the cochlea that assists in preserving balance. According to Prof. Robert Stokroos of UMCM, the first measurements after the surgery showed positive results. Very important, as far as I understand, will be whether the vestibular implant will allow for perfect integration of the balance information delivered by the implant and the balance perceived by the eyes.

Despite all this, I believe we have exciting times ahead for the application of novel neurostimulating devices.


Mission Possible

In order to present the Biomedical Electronics Group of Delft University of Technology to a couple of companies, it made sense to reveal our mission statement. So here it goes…

The mission of the Biomedical Electronics Group of Delft University of Technology is "to provide the technology for the successful monitoring, diagnosis and treatment of cortical, neural, cardiac and muscular disorders by means of electricity." In order to reach this goal we investigate and design circuits and systems for electrical stimulation, ExG readout, signal specific analog signal processing, power management/conversion, energy harvesting and wireless communication, to be applied in future wearable and implantable medical devices, such as hearing instruments, cardiac pacemakers, cochlear implants and neurostimulators.

So how about that? Reactions are welcome via this blog.


Fanmail from China

Today, we received the following feedback on the course Analog Integrated Circuit Design (ET4252), which is available under the Open CourseWare program:



student ding


<email address removed>

Where are you from?


You had a(n):


What was your feedback about?

Analog Integrated Circuit Design

Your Feedback was:

The video is so cool that I love it very much. IT seems doesn’t contain all
lectures, I am really want to see all the lectures in video.
I am a senior in university from China.
Thank you very much.

Thank you very much, Ding! You definitely make my day.