Post 5: Project Outline

Project Outline:

  1. Problem: Lithium batteries
    1. Dependency on batteries and external energy sources has really limited the compatibility of several possible healthcare devices and make it harder for patients to constantly have peace of mind.
      1. Toxic material
      2. Lacks longevity
      3. Heavy
      4. Non-flexible
      5. Nonrenewable
  2. Introduce topic of harnessing energy from human body
    1. How much power the human body holds/is capable of generating
    2. Why this source of energy is better than lithium batteries
    3. Different areas of harnessing power
      1. Movement (piezoelectricity)
      2. Heat (thermodynamics)
      3. Glucose Fuel Cells (Enzymatic Fuel Cells)
  3. Current Technology
    1. Glucose-based fuel cells
      1. The use of glucose enzymatic fuel cells will allow users to use various nanotechnological devices that could allow patients to monitor various portions of the body, allow easier application of medications, reducing the need for constant monitoring and aid from nurses and loved ones.
      2. Explain how they work
      3. Explain the challenges
        1. Interfacing with human body
    2. Specifically Enzymatic fuel cells
  4. Our decision to focus on EFCs
    1. Why we chose EFCs
      1. Because they are the most natural form of harnessing power from the body over the other forms
      2. Take electrons from the glucose in the plasma of our blood
    2. What is the largest benefit of using them over other technology
    3. What are the challenges still
      1. Direct Electron Transfer (DET)
      2. Mediated electron transfer (MET) – finding the right molecule
        1. It has been shown that the correct composition of the molecule mediating the transfer of electrons can idealize the amount of power generated
        2. This molecule must have the right potential to allow electrons to most easily be transferred
  5. Our Technology/ Idea
    1. What it is/how it works…
      1. These are enzymatic fuel cells that oxidize glucose through redox reactions in order to transfer the electrons from the glucose in the plasma in our blood and create an electric potential/electricity.
    2. Why it is better…
      1. Harnesses more energy, faster – more efficient
        1. Is more natural to the human body, working with natural reactions rather than external “hardware” which the body does not simply accept
      2. More power
      3. Has potential to transfer electrons faster and at greater mass than the alternatives
  6. Possible applications for the future
    1. This application could be used in an assortment of nanotechnologies that could be used for patients that are categorized in an array of age ranges.
      1. Patients that are dependent on their blood pressure monitors could have a device implanted that can give constant updates and could alert them and their family members when it reads dangerous levels.
      2. A younger child that suffers from a heart defect or specific infections could use a implanted device to monitor their health without the discomfort or dependency of remembering to charge any device or sit by an outlet for an extended period of time.

Post 4

Our group wants to find and improve the most beneficial option for harnessing power from the human body in order to power implantable devices. We’ve decided that we want to focus on using glucose fuel cells and specifically glucose powered enzymatic fuel cells to harness the power. The existing research on these fuel cells shows challenges with the interface between the fuel cells and the human body. Since the fuel cells convert chemical energy into electrical energy by oxidizing glucose into gluconolactone and reduces oxygen into water, and glucose is abundant in the blood, these fuel cells must directly interact with bodily fluids. Due to interfacing challenges, the fuel cells are not as efficient as they could be. Our group plans to redesign an enzymatic fuel cell so that the cells can have a more efficient interaction with the body. Mediated electron transfer (MET) has been shown to enhance this process by using a molecule with a correct potential for the redox reaction to transfer the electrons from the biomass to the enzymes. If the composition of these small molecules is optimized for the body, it can actually increase the rate at which the electrons are transferred to the enzymes, and therefore generate a larger current (more power). This has been shown to have the potential to transfer electrons faster and at greater mass than the alternative, which is Direct Electron Transfer (DET), where the electrons are directly transferred to the enzymes. This idea would improve what is currently out there because it would make fuel cells that are more effective so that the energy they generate can have enough power to charge implantable devices in the body.

  • Olivia, Alec, Abdi, and Rena

Research Summary – Oct. 13

Microbial fuel cells use bacteria as the catalysts to oxidize organic and inorganic matter to generate current that supplies implantable medical devices (Logan, 2006). A critical review from Microbial Fuel Cells Focus Group at Penn State University reports that a widely used and inexpensive type of microbial fuel cell is designed with two chambers connected by a tube containing a carton exchange membrane. The choice of membrane in this design is crucial: the membrane has to allow protons to pass between the chambers, but not the substrate or election acceptor in the cathode chamber (Logan, 2006). The design of microbial fuel cells hence involves knowledge in microbiology, electrochemistry, materials, and environmental engineering. Development in microbial fuel cells has great potential to be used as a renewable and bio-compatible energy source for commercial as well as medical applications. However, it is a field of research that currently lacks established terminology  and systematic method of analysis.

Thermoelectric Power

There are available examples of technology that can convert body heat into electricity. The technology is made to where thermoelectric generators are used to harvesting electricity from body heat. This can be seen as an amazing finding for possibly powering nanotechnology that is small in size and weight, due to the lack in need of batteries and other bulky components. This could possibly be incorporated with a compatible heart rate monitor or blood sugar monitor for patients to easily access. The thermoelectric generators, only 2 millimeters in thickness, generates electricity by using the temperature differential that is found between the air surrounding the body and the body itself. Understanding this, this technology would be difficult to work with for technology that would be implanted within the body, but could be altered to fit the different environment.


Lightweight, Wearable Tech Efficiently Converts Body Heat to Electricity

Research Update 3 – Alec McKendell

It is possible to harness power from muscle contractions within the human body. By using a small electromagnetic induction generator to stimulate strong muscle contractions in different parts of the body, another device which can convert those contractions into a rotational motion can generate electricity. In a study which used a leg muscle in a frog, it was proved that it required minimal electrical power in order to stimulate the muscle, and the power which was generated from the contraction was significantly higher that what was required. This new usage of relatively simple technology has the potential to replace lithium-ion batteries in powering implantable biotechnology.



Assignment 3 – Biofuel Cell Technology

Biofuel cell technology is another option to power nanotechnology inside the human body. The article below discusses renewable biofuel cells that are glucose-based. Instead of using batteries, an implantable device can extract its source of energy from biofuel cells within the body. The article discusses how biofuel cells can convert the chemical energy of biofuels like glucose into electrical energy through oxidation. This energy could then power devices like pacemakers, insulin pumps, and other technology inside the body. Right now, glucose-based biofuel cells are limited in lifespan and production of power, but further research could make them an ideal substitute to batteries that are currently being used inside the body. Converting glucose into electrical energy to power nanotechnology is another option that our group should consider as it is sustainable source and would be a safer alternative to lithium batteries.


Research Update 2 – Alec McKendell

The average adult human has about the same amount of energy stored within their body as a 1 ton battery.

Current designs for implants in knees, both through transplant surgeries and braces can harvest kinetic energy to power small devices. Other devices harnessing the power of thermodynamics and kinetic energy have been used in constantly changing/moving parts of the human body such as the heart, lungs, legs, etc.

Another source of energy is the endocochlear potential – a potential generated in the space in the ear across the membrane. This potential created from vibrations in the eardrum has enough power to theoretically power a small hearing aid/device. This could result in the first piece of biotech which is fully powered by the body, and is one step closer to actual integration.



Research Summary-Lithium Batteries

Since the introduction of the pacemaker, lithium batteries were used to sustain power in implantable medical devices. Reasons that lithium batteries were the most popular power source include their comparatively compact sizes and long durability up to 10 years (approaches). However, there are safety risks and compatibility difficulties involved with using lithium batteries in a human body. Understanding these challenges gives context to the significance of our group’s research on alternative energy sources to implantable medical devices. Take a look at the usage of lithium batteries in pacemakers. There are two sources of biological incompatibility between lithium batteries and the human body. Lithium has extremely high specific heat, making it an ideal source of energy. However, because reacts violently with water, non-aqueous electrolytes must be used. Because most biological reactions occur in an aqueous environment, lithium batteries are hence incompatible to the environment within the human body. Secondly, electrical impulses are transmitted to the heart by a lead, which is attached to the pulse generator on the pacemaker by the connector block. The tip of the lead is implanted into the endocardial surface of the heart (trends). Metals are also a highly incompatible material with biotic tissues.



Powering with Glucose

One source of energy that I came across an article mentioning of a single implanted glucose biofuel cell, or GBFC, that is capable of generating sufficient power from a mammal’s bodily fluids to act as a power source for electronic devices. This type of energy generation would be the most suitable for bio/nanotechnology that would be within the body. One of the most intriguing portions of the report was that the implant didn’t have any signs of rejection or inflammation within the rat after nearly four months of the cell being implanted in the abdominal cavity. The autopsies even showed within the first two to three weeks that a thin layer of vascularized tissue begins to cover the external side of the implant, ensuring how biocompatible it would be. With this in mind, I would also begin to think about how the energy would be stored efficiently and then used appropriately for various technologies? Would the human body have the same reaction to such an implant?



Energy from Human Motion

Assignment 2:

Human movement is another source of energy that can be harvested to power nanotechnology. One article I found discusses the research done at Vanderbilt University to harvest energy from low-frequency human motion (as slow as 0.01 Hertz). Ultrathin layers of black phosphorous nanosheets are being used to extract energy directly from human motion. The materials developed are so thin that they can be easily incorporated into clothing. According to another article, MIT researchers found a new method to harness energy from human movements. They developed a flexible electrochemical battery that begins to bend with human motion. Pressure builds up when the battery bends and an electrical current is made. This current can then be used to power other nanodevices. As we consider how we want to harvest energy to power nanotechnologies inside the body, our group might think about the ways in which humans create energy and how this energy can be transferred for internal use.