Printable, Temporary Tattoo-like Medical Sensors are Under Development

pulse-trace-163708_640There is a new high-energy action and suspense drama on NBC this year called Blindspot. The first episode began when a woman in left in a luggage bag in the middle of Times Square in New York with tattoos completely covering her and absolutely no memory of who she is or how she got there. She is taken in by the FBI who starts to analyze her tattoos and see if they can figure out who she was before her memory was intentionally destroyed. It turns out that the tattoos are puzzles that, once solved, start to lead a team of agents assigned to her to a series of dangerous criminal operations.

“Jane” as they call her, is quickly made a part of this FBI team because, without knowing why, she immediately exhibits professional level fighting and weapons skills. She is also highly motivated to find out her real identity and is starting to experience brief memory flashbacks. All sorts of subplots and machinations have begun to sprout up regarding her true identity and how she ended up in this dilemma.

So far, the show is doing well in the ratings. Imho, after four episodes it’s off to a compelling and creative start. I plan to keep watching it. (The only minor thing I don’t like about it is the way the production team is using the shaky cam so much it’s making me feel a bit seasick at times.)

The lead actress, Jamie Alexander, who plays Jane, is actually wearing just temporary tattoos on the show. While these cryptic designs are the main device to propel the fictional plots forward in each episode, back in the non-fictional real world temporary tattoo-like devices are also currently being tested by researchers as medical sensors to gather patients’ biological data. This news adds a whole new meaning to the notion of medical application.

This advancement was reported in a most interesting article on Smithsonian.com, posted on October 8, 2015 entitled Tiny, Tattoo-Like Wearables Could Monitor Your Health, by Heather Hansman. I will summarize and annotate it in an effort to provide a, well, ink-ling about this story, and then pose some of my own questions.

Research and Development

This project, in a field called bio-integrated electronics, is being conducted at the University of Texas at Austin’s Cockrell School of Engineering. The research team is being led by Professor Nanshu Lu (who received her Ph.D. from Harvard).  Her team’s experimental patch is currently being applied to test heart rates and blood oxygen levels.

When Dr. Lu and her team were investigating the possibility of creating these “tattoo-like wearables”, their main concern was the manufacturing process, not the sensors themselves because there were many already available. Instead, they focused upon creating these devices to be both disposable and inexpensive. Prior attempts elsewhere had proven to be more “expensive and time-consuming”.

This led them to pursue the use of  3D printing . (These four Subway Fold posts cover other applications of this technology.) They devised a means to print out “patterns on a sheet of metal instead of forming the electronics in a mold”. They easily found the type of metal material for this purpose in a hardware store. Essentially, the patterns were cut into it rather than removed from it. Next, this electronic component was “transfer printed onto medical tape or tattoo adhesive”. Altogether, it is about the size of a credit card. (There is a picture of one at the top of the article on Smithsonian.com linked above.)

The entire printing process takes about 20 minutes and can be done without the use of a dedicated lab. Dr. Lu is working to get the cost of each patch down to around $1.

Current Objectives

The teams further objective is to “integrate multiple sensors and antenna” into the patches in order to capture vital signs and wirelessly transmit them to doctors’ and patient’s computing devices.  They can be used to measure a patient’s:

One of the remaining issues to mass producing the patches is making them wireless using Bluetooth or near field communication (NFC) technology. At this point, chip producers have not made any commitments to make such chips small enough. Nonetheless, Dr. Lu and her team are working on creating their own chip which they expect will be about the size of a coin.

My Questions

  • Could this sensor be adapted to measure blood glucose levels? (See a similar line of research and development covered in the June 27, 2015 Subway Fold post entitled Medical Researchers are Developing a “Smart Insulin Patch”.)
  • Could this sensor be adapted to improve upon the traditional patch test for allergies?
  • Could this sensor be adapted for usage in non-vital sign data for biofeedback therapies?
  • Would adding some artwork to these patches make them aesthetically more pleasing and thus perhaps more acceptable to patients?
  • Could this sensor be further developed to capture multiple types of medical data?
  • Are these sensors being secured in such a manner to protect the patients’ privacy and from any possible tampering?
  • Could the production team of Blindspot please take it easy already with the shaky cam?

Medical Researchers are Developing a “Smart Insulin Patch”

“Spinning Top”, Image by Creativity103

April 9, 2018 Update: This post was originally uploaded on June 27, 2015. It has been updated with new information below.


In an innovative joint project at the University of North Carolina and at North Carolina State University, medical researchers are currently developing a “smart insulin patch” that can both measure blood glucose levels and then administer insulin to regulate it as needed for people with Type 1 diabetes. This is yet another approach at the core of much academic and commercial research and development at creating a “closed loop” system that senses and responds to changes in blood sugar.

Other ongoing research in this field is attempting to integrate continuous glucose sensors with insulin pumps, both of which are available on the market but not yet working together in a viable product with regulatory approval. Both of these approaches are efforts to create a biomedical system that can act as a fully functioning artificial pancreas for people with Type 1 diabetes.

The ongoing work on the smart insulin patch was covered in a fascinating article in the June 22, 2015 edition of The Washington Post entitled The ‘Smart’ Insulin Patch That Might One Day Replace Injections for Diabetic Patients by Brady Dennis. I will summarize, annotate and add a few questions of my own. (Two other recent Subway Fold posts on  October 3, 2014 and June 16, 2015, clickable here and here, respectively, have covered one project to upload glucose monitoring data to the mobile devices of friends and relatives, and another by a medical device manufacturer using social media to reach out to people using insulin pumps.)

This new smart insulin patch is a square shape as small as a penny and is word on the skin. One side of it contains numerous tiny “microneedles” that the face the skin and contain “both insulin and a glucose-sensing enzyme”. Thus, when an increase in blood glucose is detected, the patch can release insulin into the patient’s system “quickly and painlessly”. As a result, the necessity for the delivering insulin by traditional means of a syringe or insulin pump is eliminated.

To date, the development team has only tested the patch on mice. Early test results, published here in The Proceedings of the National Academy of Science (subscription required), showed that the patch worked on the test animals starting within 30 minutes of its application and then lasting for up to nine hours.

Dr. John Buse, one of the co-authors and the director of the UNC Diabetes Center, finds this “exciting”, but he also believes it will take years to determine if this will work in humans. A very informative and detailed news release with photos of the patch and the microneedles, entitled Smart Insulin Patch Could Replace Painful Injections for Diabetes, has recently posted on the UNC Diabetes Center website.

Using current technology requires people with Type 1 diabetes to check their blood glucose levels a number of times each day and then corresponding regulate their insulin to balance the effects of these up and down readings. Other researchers have endeavored to “closed the loop” between insulin pumps and continuous glucose monitors, but these systems still require close attention and adjustments by the patient

The smart insulin patch, if proven safe and viable, could one day dramatically change protocols for the care of Type 1 diabetes. It is an attempt to more directly emulate the human body’s own insulin regulatory system. As well, the microneedles in the patch are designed to be far less invasive and nearly painless than today’s use of injections, pumps and sensors, all of which require larger needles to pierce the skin. It is designed to directly “tap into the blood flowing through the capillaries” in order to become activated.

The researcher team has also found that they could “fine tune the patch” to attain blood glucose levels within an acceptable range. As a result, they are hopeful that, in the future, the patch could be adjusted to each individual patient’s system (including, among other things, weight and insulin sensitivity), and the duration of the patch’s effectiveness could be extended to several days.

My questions are as follows:

  • How exactly will the patch be personalized to meet the biological needs of each user? How will patients manage and regulate this from patch to patch? Is the goal to calibrate a single patch for the user or a series of patches as the user’s needs and environment changes?
  • Can the patches be customized and fabricated using today’s commercial 3D printing technology?
  • Will blood glucose levels still need to be checked regularly using current methods in order to assess and align the patch’s effectiveness and accuracy?
  • Can the patch’s data on blood glucose levels and insulin dosages be uploaded onto mobile devices in order to be monitored by the patient’s health professionals and family members?
  • Might the patch be used in conjunction with or even integrated into the Apple Watch as a medical app?
  • Can other medications that a person with diabetes is taking also be administered, monitored and regulated with the patch, perhaps making it even “smarter”?

April 9, 2018 Update: For a report on the latest research into non-invasive smart patches being used to measure blood glucose levels, a new article has just been posted today, April 9, 2018, on Nature.com entitled Non-invasive, Transdermal, Path-Selective and Specific Glucose Monitoring Via a Graphene-based Platform, by Luca Lipani, Bertrand G. R. Dupont, Floriant Doungmene, Frank Marken, Rex M. Tyrrell, Richard H. Guy & Adelina Ilie. Nature.com is a subscription-only site with the link provided here just to an abstract of the article. Nonetheless, it provides a most interesting introduction about this ongoing research. My question after seeing this is whether there is now, or will be in the future, any possibility that this technology and the insulin delivery research described in the main post above, will be integrated to form the basis of a closed-loop or artificial pancreas system that will both monitor blood glucose levels and deliver insulin in as needed response.