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Open AccessEditorial

Statement of Peer Review

by Willem Perold

Eng. Proc. 2025, 109(1), 1; https://doi.org/10.3390/engproc2025109001 - 4 Sep 2025

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Abstract

In submitting conference proceedings to Engineering Proceedings, the Volume Editors of the proceedings would like to certify to the publisher that all papers published in this volume have been subjected to peer review by the designated expert referees and were administered by [...] Read more.

In submitting conference proceedings to Engineering Proceedings, the Volume Editors of the proceedings would like to certify to the publisher that all papers published in this volume have been subjected to peer review by the designated expert referees and were administered by the Volume Editors strictly following the policies and procedures in Appendix A [...] Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

5 pages, 172 KB

Open AccessEditorial

Preface: Micro Manufacturing Convergence Conference

by Willem Perold

Eng. Proc. 2025, 109(1), 2; https://doi.org/10.3390/engproc2025109002 - 4 Sep 2025

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Abstract

The Micro Manufacturing Convergence Conference 2024 (MMC 2024) is hosted by Stellenbosch University’s Department of Electrical and Electronic Engineering, in partnership with the Department of Science and Innovation (DSI) and the Nano-Micro Manufacturing Facility (NMMF) [...] Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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4 pages, 831 KB

Open AccessProceeding Paper

Rapid, Low-Cost Production of Multilayer Molds for PDMS Lab-on-Chip Devices

by Eldas M. Maesela, Mandla Msimanga, Masibulele Kakaza and Manfred R. Scriba

Eng. Proc. 2025, 109(1), 3; https://doi.org/10.3390/engproc2025109003 - 8 Sep 2025

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Abstract

We present a simple, rapid and low-cost multi-layer mold fabrication method for production of polydimethylsiloxane (PDMS) lab-on-chip (LOC) devices. The new approach offers resource-strained researchers access to microfluidic lab-on-chip fabrication for medical diagnostics, food security and environmental monitoring applications. In this work, photomasks [...] Read more.

We present a simple, rapid and low-cost multi-layer mold fabrication method for production of polydimethylsiloxane (PDMS) lab-on-chip (LOC) devices. The new approach offers resource-strained researchers access to microfluidic lab-on-chip fabrication for medical diagnostics, food security and environmental monitoring applications. In this work, photomasks were designed on PowerPoint (2021) and printed on Pelikan transparency sheets using a Canon PIXMA iX6840 Inkjet printer. The photomasks were then tested for ultraviolet (UV) transmission and compared to the masks produced for circuit board manufacture. Another low-cost approach for the alignment of multi-exposure masks was also developed and tested by producing three-layer photoresist pyramid-like structures on silicon (Si) wafer using the soft lithography process. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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6 pages, 1403 KB

Open AccessProceeding Paper

Rapid Route to Lab-on-Chip (LOC) Prototype Fabrication with Limited Resources

by Manfred Scriba, Masibulele Kakaza, Eldas Maesela and Vusani Mandiwana

Eng. Proc. 2025, 109(1), 4; https://doi.org/10.3390/engproc2025109004 - 10 Sep 2025

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Abstract

Several approaches to producing lab-on-chip (LOC) devices have been developed in the last 20 years, including laser cutting of acrylic sheets and laminating them with adhesive films. While this route allows for rapid manufacture of devices, it cannot be scaled up beyond a [...] Read more.

Several approaches to producing lab-on-chip (LOC) devices have been developed in the last 20 years, including laser cutting of acrylic sheets and laminating them with adhesive films. While this route allows for rapid manufacture of devices, it cannot be scaled up beyond a couple of prototypes. For mass production of 3D LOC devices, injection molding is required, but mold manufacturing can be very costly. In this work we briefly report laser cutting parameters and lamination approaches, as well as 3D-printed injection mold inserts that allow one to produce LOC prototypes in facilities that have limited resources. This allows these facilities to transition from a couple of demonstrators to more than 100 devices in a short time and with limited costs. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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6 pages, 919 KB

Open AccessProceeding Paper

Comparison of Modifications of Cellulose for the Extraction and Elution of DNA

by Shannon Megan Rutherford, Janice Limson and Ronen Fogel

Eng. Proc. 2025, 109(1), 5; https://doi.org/10.3390/engproc2025109005 - 11 Sep 2025

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Abstract

The extraction of DNA from biological samples precedes many research and commercial applications. This study compares surface treatments of cellulose (a low-cost binding matrix) to enhance binding and elution of DNA to paper-based dipsticks. Cellulose paper was modified with poly-L-lysine, silica, or guanidine, [...] Read more.

The extraction of DNA from biological samples precedes many research and commercial applications. This study compares surface treatments of cellulose (a low-cost binding matrix) to enhance binding and elution of DNA to paper-based dipsticks. Cellulose paper was modified with poly-L-lysine, silica, or guanidine, as well as subjected to TEMPO-based oxidation. Subsequently, binding and elution behaviour of fragmented salmon sperm DNA to dipsticks was evaluated. Qubit fluorimetry and agarose gel electrophoresis measurements indicated that TEMPO-based oxidation significantly increased the binding of DNA and its elution from dipsticks, while silica modifications bound DNA efficiently, but strongly retained it. Leaching of select modifiers (guanidine, silica and poly-L-lysine) was indicated by UV/Vis spectroscopy, indicating that further optimization of attachment processes is required. This study is the first to compare multiple cellulose surface treatments for their influence on DNA binding and elution, especially the use of TEMPO-based oxidation for this purpose, and highlights some means of identifying leaching of modifiers during DNA capture at these surfaces and subsequent elution. While TEMPO-based oxidation proves a promising treatment to enhance DNA elution, further refinement of the approach is needed to ensure compatibility with molecular biology techniques. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 1050 KB

Open AccessProceeding Paper

In Vitro Cytotoxicity of Single Walled Carbon Nanotube Bioconjugates on Cancer Cells

by Zvikomborero T. Gwanzura, Willem J. Perold and Anna-Mart Engelbrecht

Eng. Proc. 2025, 109(1), 6; https://doi.org/10.3390/engproc2025109006 - 11 Sep 2025

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Abstract

Carbon nanotubes have shown great promise in drug delivery systems as they can easily penetrate the cell membrane. Herein, carbon nanotubes functionalized with polyethylene glycol and folic acid were used to improve target specificity in breast and colon cancer cells. The functionalized carbon [...] Read more.

Carbon nanotubes have shown great promise in drug delivery systems as they can easily penetrate the cell membrane. Herein, carbon nanotubes functionalized with polyethylene glycol and folic acid were used to improve target specificity in breast and colon cancer cells. The functionalized carbon nanotubes were bioconjugated with bioactive compounds from plant extracts. In vitro cytotoxicity studies were conducted to demonstrate cellular uptake and apoptosis due to bioconjugate cellular internalization. The bioconjugates were able to preserve normal cells and induce cell death in cancer cells. The efficacy of the carbon nanotube bioconjugates in this study shows great potential in cancer therapy applications. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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8 pages, 1109 KB

Open AccessProceeding Paper

NGS-Guided Aptamer Re-Selection for Improved Sensor Applications: Biotin as a Modification Tag in the Amplification of Enriched Pools

by Tasmita Singh, Ronen Fogel and Janice Limson

Eng. Proc. 2025, 109(1), 7; https://doi.org/10.3390/engproc2025109007 - 12 Sep 2025

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Abstract

Aptasensors are biosensors that rely on an aptamer’s ability to selectively bind targets. To produce a signal indicative of successful binding, aptamers are frequently modified with reporter agents. However, modification of aptamers with specific reporter agents affects subsequent aptamer-target binding, resulting in time-consuming [...] Read more.

Aptasensors are biosensors that rely on an aptamer’s ability to selectively bind targets. To produce a signal indicative of successful binding, aptamers are frequently modified with reporter agents. However, modification of aptamers with specific reporter agents affects subsequent aptamer-target binding, resulting in time-consuming screening assays to identify suitable aptamers capable of binding, once modified. To address this, this study proposes a SELEX approach that amplifies an enriched aptamer pool using a 5′-biotin-C6-phosphoramidite modification and using that for subsequent selection of suitable sequences capable of binding when modified. For this study, fractions from an existing enriched aptamer pool from a previous SELEX for hCG aptamers were separately amplified utilising biotinylated and non-biotinylated (unmodified) primers and sequenced via nanopore next-generation sequencing. While several enriched sequences were represented within the pools, bioinformatic analysis of the pools indicated subtle clustering of sequences between pools. However, the disparity in the number of sequences between both pools may indicate a possible amplification or sequencing-based bias caused by the biotinylation. This approach has merit to support aptamer SELEX strategies but may require further validation. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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4 pages, 204 KB

Open AccessProceeding Paper

In-Plane Thermoelectric Characterisation of PEDOT:PSS Films with Inkjet-Printed Test Structures

by Promise Msomi and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 8; https://doi.org/10.3390/engproc2025109008 - 11 Sep 2025

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Abstract

A rapid screening method to identify suitable candidate inks for printed electronics applications is necessary. Herein, we investigate the in-plane thermoelectric properties of PEDOT:PSS for energy harvesting applications on human skin using silver nanoparticle inkjet-printed test structures. The in-plane electrical and thermal conductivity [...] Read more.

A rapid screening method to identify suitable candidate inks for printed electronics applications is necessary. Herein, we investigate the in-plane thermoelectric properties of PEDOT:PSS for energy harvesting applications on human skin using silver nanoparticle inkjet-printed test structures. The in-plane electrical and thermal conductivity are measured. The Seebeck coefficient, ZT figure of merit, and power factor are consequently determined. PEDOT:PSS films resulted in low-efficiency thermoelectric properties at 293 K to 313 K and demonstrated a correlation between film thickness and in-plane thermoelectric properties. This study demonstrates that the test structures enable generalisable characterisation of thin-film inkjet-printable materials for thermoelectric purposes. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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6 pages, 1056 KB

Open AccessProceeding Paper

An Africa Lateral Flow Assay-Based Early Recognition Test for Tenofovir-Induced Acute Kidney Injury (ALERT-AKI) Development

by Amanda Skepu, Nolwandle Nxumalo and Sibongile Phiri

Eng. Proc. 2025, 109(1), 9; https://doi.org/10.3390/engproc2025109009 - 12 Sep 2025

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Abstract

The prevalence of (TDF)-induced Acute Kidney Injury (AKI) in Africa is a concern, given the widespread use of Tenofovir disoproxil fumarate (TDF) for Human Immunodeficiency Virus (HIV) therapy. Current tests used to detect AKI are based on increased urinary creatinine levels and are [...] Read more.

The prevalence of (TDF)-induced Acute Kidney Injury (AKI) in Africa is a concern, given the widespread use of Tenofovir disoproxil fumarate (TDF) for Human Immunodeficiency Virus (HIV) therapy. Current tests used to detect AKI are based on increased urinary creatinine levels and are often not sensitive and specific enough for early detection. There is a need for more sensitive and specific rapid tests for the early detection of AKI, particularly in resource-limited countries for early detection and timely intervention. In the present study, a multiplex lateral flow assay, named An Africa Lateral Flow Assay-Based Early Recognition Test for Acute Kidney Injury (ALERT-AKI), detecting a set of three unique biomarkers of TDF-induced AKI was developed with a limit of detection of 2 ug/mL to 50 ug/mL, indicating the suitability of developed test for determining the selected AKI biomarkers in a clinically relevant range. This study shows proof of concept for a multiplex lateral assay tested on clinical samples. The ALERT-AKI multiplex platform will be the first of its kind once further clinical studies are conducted, offering multiple advantages, including early detection, simplicity, rapidity, high sensitivity, cost-effectiveness, and timely intervention, potentially reducing the severity and prevalence of AKI. Using a multiplexed protein biomarker rather than single protein molecules will allow for a much more accurate detection of kidney damage before it becomes significant or irreversible. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 1493 KB

Open AccessProceeding Paper

Paired Emitter–Detector Diode Array for Colorimetric Detection of Water Treatment Chemicals

by Duane Olivier and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 10; https://doi.org/10.3390/engproc2025109010 - 13 Sep 2025

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Abstract

Optical spectroscopy is a versatile analytical technique with a diverse range of applications. Point-of-need systems are required to be affordable, miniaturized instruments that are easy to use. This paper proposes using an array of LEDs to create paired emitter detector diodes where commercial [...] Read more.

Optical spectroscopy is a versatile analytical technique with a diverse range of applications. Point-of-need systems are required to be affordable, miniaturized instruments that are easy to use. This paper proposes using an array of LEDs to create paired emitter detector diodes where commercial LEDs function as both a light source and detector. This system can measure the concentration of different chemicals via a set of discrete wavelengths. Calibration curves are presented for series of known concentrations of three water treatment chemicals using the K-matrix method. The spectral fingerprint identifies the chemical correctly with 99% accuracy using the Pearson correlation. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 1406 KB

Open AccessProceeding Paper

Data Analysis and Modelling of a Sodium Salt Matrix with Low-Cost Impedance Spectroscopy

by Dirk J. De Beer and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 11; https://doi.org/10.3390/engproc2025109011 - 12 Sep 2025

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Abstract

This study investigates the use of impedance spectroscopy for fingerprinting aqueous salt solutions. By analysing solutions containing Sodium Nitrate (

{NaNO}_{3}

), Sodium Sulphate (

{Na}_{2} {SO}_{4}

), and their mixtures, we explore how impedance data can potentially be used [...] Read more.

This study investigates the use of impedance spectroscopy for fingerprinting aqueous salt solutions. By analysing solutions containing Sodium Nitrate (

{NaNO}_{3}

), Sodium Sulphate (

{Na}_{2} {SO}_{4}

), and their mixtures, we explore how impedance data can potentially be used to distinguish between different salt compositions and concentrations. Our findings demonstrate the potential of this method for precise solution characterisation as well as highlighting the benefits of access to low-cost impedance analysers such as the one used for this investigation. More research and data is required to fully realise the potential of this approach. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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6 pages, 540 KB

Open AccessProceeding Paper

Development of a Biosensor for the Early Detection of Tuberculous Meningitis in Infants

by Dabin Kim, Willem Jacobus Perold and Novel N. Chegou

Eng. Proc. 2025, 109(1), 12; https://doi.org/10.3390/engproc2025109012 - 15 Sep 2025

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Abstract

Tuberculous meningitis (TBM) is a severe illness that is predominantly observed in countries with a high burden of tuberculosis. It is primarily found in infants and human immunodeficiency virus (HIV)-infected adults, and, if left untreated, causes irreversible damage to the host’s nerve and [...] Read more.

Tuberculous meningitis (TBM) is a severe illness that is predominantly observed in countries with a high burden of tuberculosis. It is primarily found in infants and human immunodeficiency virus (HIV)-infected adults, and, if left untreated, causes irreversible damage to the host’s nerve and brain tissue, often leading to mortality. Current methods of TBM detection relies on cerebrospinal fluid (CSF) culture, which may only yield results in up to 6 weeks, is not very sensitive, and requires a biological safety level III laboratory to conduct. Other detection methods are equally not very sensitive and laborious. This research investigates the detection of interferon-gamma (IFN-γ) protein biomarker using fluoroimmunoassay with an optical biosensor and a custom-manufactured chip. The glass-surface of the chip was treated with 3-aminopropyltriethoxysilane (APTES) and incubated with glutaraldehyde to prepare for immobilization, after which a sandwich ELISA format was used to perform a dilution series by immobilizing the capture antibody, IFN-γ protein, and fluorescein isothiocyanate (FITC)-stained detection antibody onto the chip. The optical biosensor excited the FITC-stained antibodies to capture the emission light at multiple exposures, which were then merged to create a high dynamic range (HDR) image for image processing. The results from the optical biosensor were verified with a Zeiss LSM780 confocal microscope (Carl Zeiss (Pty) Limited, Cape Town, South Africa). The system demonstrated the capability to rapidly identify the biomarker, detect the binding sites, and quantify IFN-γ in blood serum. This fluorescent optical sensor proposes a possible approach for the development of a point-of-care system for TBM, providing a quicker and simpler method for the early detection of TBM. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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4 pages, 742 KB

Open AccessProceeding Paper

Development of a Microfluidic Liquid Dispensing System for Lab-on-Chips

by Masibulele T. Kakaza and Manfred R. Scriba

Eng. Proc. 2025, 109(1), 13; https://doi.org/10.3390/engproc2025109013 - 16 Sep 2025

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Abstract

This paper presents an innovative and low-cost approach to the dispensing of multiple liquids on a microfluidic chip with the aim of dispensing liquids in a controlled sequence. The project focused on the design and development of a microfluidic liquid dispensing system that [...] Read more.

This paper presents an innovative and low-cost approach to the dispensing of multiple liquids on a microfluidic chip with the aim of dispensing liquids in a controlled sequence. The project focused on the design and development of a microfluidic liquid dispensing system that is an integral part of the Lab-on-Chip (LOC). Liquids are often dispensed into LOCs through blisters, syringes, or electric microfluidic pumps, but these can be impractical for Point-of-Care (POC) settings, especially in remote areas. Additionally, incorrect volumes of biochemical reagents and the introduction of reagents outside the sequence can distort the results of the diagnosis. The process undertaken involved designing and 3D printing prototypes of the dispensing system, along with laser cutting and manufacturing the Polymethyl Methacrylate (PMMA) LOC devices intended for receiving the liquids. The proposed novel low-cost dispensing system uses manually operated actuators and cams to disperse metered fluids sequentially to minimise end-user errors at POC settings. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 600 KB

Open AccessProceeding Paper

Addressing Manufacturing and Cost Challenges Toward Solving Low-Cost In Situ Digital Holographic Microscopy Problems

by Larissa Hurter, Heinrich Edgar Arnold Laue and Johan Schoeman

Eng. Proc. 2025, 109(1), 14; https://doi.org/10.3390/engproc2025109014 - 16 Sep 2025

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Abstract

Digital holographic microscopes provide a microscopy solution with a resolution in the low-micrometre range that offers similar performance to optical microscopy, but as a relatively low-cost alternative. The most significant cost saving is due to the ability to reconstruct microscopic images from holograms [...] Read more.

Digital holographic microscopes provide a microscopy solution with a resolution in the low-micrometre range that offers similar performance to optical microscopy, but as a relatively low-cost alternative. The most significant cost saving is due to the ability to reconstruct microscopic images from holograms using low-cost components without the need for an optical stack. The cost saving opens up the avenue towards a feasible solution for geographically distributed in situ microscopic sensing in rural areas for problems like air and water pollution monitoring. The most significant contributors to cost are the camera sensor module, the pinhole, and the processing platform. The latter two components are addressed, at least in part, in this work. We successfully manufactured sub-100

μ

m diameter pinholes using ultraviolet (UV) laser cutting with an LPKF printed circuit board (PCB) prototyping platform and present the low-cost micromachining method. The pinholes were utilised within a prototype field-programmable gate array (FPGA) demonstrator that successfully reconstructed the holographic images. The choice for the FPGA approach as the initial step, albeit more complex, lends itself towards the easier development of a dedicated reconstructed application-specific integrated circuit (ASIC) to ultimately drive the cost down even further. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 795 KB

Open AccessProceeding Paper

Development of a Nano- and Microfiber Mesh-Based Biosensor for the Rapid Quantification of Human C-Reactive Protein (CRP)

by Alexander Lloyd, Willem Perold and Pieter Fourie

Eng. Proc. 2025, 109(1), 15; https://doi.org/10.3390/engproc2025109015 - 19 Sep 2025

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Abstract

Recent investigations into C-reactive protein (CRP) dynamics have shown that by evaluating the change in CRP level in a patient over time, it is possible to distinguish between bacterial and viral infections more accurately thereby guiding antimicrobial prescription practices. Consequently, a biosensor targeted [...] Read more.

Recent investigations into C-reactive protein (CRP) dynamics have shown that by evaluating the change in CRP level in a patient over time, it is possible to distinguish between bacterial and viral infections more accurately thereby guiding antimicrobial prescription practices. Consequently, a biosensor targeted towards CRP was developed using a nano- and microfiber mesh-based transducer. The produced transducers were functionalized with streptavidin, after which a biorecognition element, anti-CRP antibodies, could be bound to the sensor. Confirmation of the sensor production phases was obtained using fluorescence microscopy. The sensors were evaluated using Electrochemical Impedance Spectroscopy (EIS) and showed increasing changes in the impedance modulus corresponding to increasing concentrations of CRP in solution following a parabolic trend line. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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4 pages, 15624 KB

Open AccessProceeding Paper

Microfabrication of an e-QR Code Sensor Display on a Flexible Substrate

by Asha Elizabeth Raju, Heinrich Edgar Arnold Laue and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 16; https://doi.org/10.3390/engproc2025109016 - 19 Sep 2025

Viewed by 505

Abstract

Electronic quick response (e-QR) codes provide access to real-time sensor data using smartphone readers and internet connectivity. Printed electronics and hybrid integration on flexible substrates is a promising solution for wide-scale and low-cost deployment of sensor systems. This paper presents a 21 × [...] Read more.

Electronic quick response (e-QR) codes provide access to real-time sensor data using smartphone readers and internet connectivity. Printed electronics and hybrid integration on flexible substrates is a promising solution for wide-scale and low-cost deployment of sensor systems. This paper presents a 21 × 21-pixel e-QR display implemented on black Kapton using hybrid additive and subtractive microfabrication techniques. The process flow for the double-sided circuit allows for layer alignment using multiple fiducial markers. The steps include inkjet printing of tracks on both sides of the substrate, laser-cut via holes, stencil-aided via filling, solder paste dispensing, and final integration of discrete surface-mount components by semi-automatic pick-and-place. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 1621 KB

Open AccessProceeding Paper

Towards a Wearable Skin Tone Responsive Optical Sensor

by Nomakhosi N. Ndiweni and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 17; https://doi.org/10.3390/engproc2025109017 - 22 Sep 2025

Viewed by 821

Abstract

Melanin is one of the key light absorbers in skin and is responsible for the colour of the skin. This study evaluates the responsivity of different skin tones to white light within the visible spectral range of 300–700 nm on 12 participants. The [...] Read more.

Melanin is one of the key light absorbers in skin and is responsible for the colour of the skin. This study evaluates the responsivity of different skin tones to white light within the visible spectral range of 300–700 nm on 12 participants. The results show that the peak amplitude of the reflected light signal decreased by 90% for darker skin tones, compared to 70% for lighter skin tones. There were also visible differences at the 460 nm and 570 nm wavelengths between the skin tones, suggesting that the standard one-glove-fits-all pulse oximeter might not be ideal. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 1111 KB

Open AccessProceeding Paper

Electrode Thickness Optimization in Color-Selective Inkjet-Printed Photosensitive Organic Field-Effect Transistors

by Christoph Steger, Ali Veysel Tunc, Christian Rainer, Ozan Karakaya, Dario Mager, Luis Ruiz Preciado, Trudi-H. Joubert, Uli Lemmer and Gerardo Hernandez-Sosa

Eng. Proc. 2025, 109(1), 18; https://doi.org/10.3390/engproc2025109018 - 24 Sep 2025

Viewed by 528

Abstract

This work introduces a general solution for printing wavelength-selective bulk-heterojunction photosensitive organic field effect transistors (PS-OFETs) by addressing electrode thickness variation and the feasibility of color selectivity in detecting incident light. The inkjet-printed silver electrode thickness was varied from 125 to [...] Read more.

This work introduces a general solution for printing wavelength-selective bulk-heterojunction photosensitive organic field effect transistors (PS-OFETs) by addressing electrode thickness variation and the feasibility of color selectivity in detecting incident light. The inkjet-printed silver electrode thickness was varied from 125 to

950 n m

by multilayer printing. PIF, IDFBR, and ITIC-4F were chosen as the active semiconductor materials with complementary optical absorption. Results indicate that PS-OFETs exhibit the best functionality at an electrode thickness of approximately

325 n m

and an active material combination with PIF:IDFBR (1:1). For the

540 n m

wavelength, a responsivity of

55 m A W^{- 1}

was obtained. This is four-fold higher than the photoresponse obtained at

700 n m

. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 483 KB

Open AccessProceeding Paper

Nanoparticle-Mediated Drug Delivery: Enhancing Therapeutic Efficacy and Minimizing Toxicity

by Andrew Waititu, Tabitha Waithira and Allan Mwaura

Eng. Proc. 2025, 109(1), 19; https://doi.org/10.3390/engproc2025109019 - 2 Oct 2025

Cited by 1 | Viewed by 879

Abstract

This research focuses on developing innovative nanoparticle-based drug delivery systems to enhance therapeutic efficacy while minimizing adverse effects. We engineered biocompatible polymeric nanoparticles capable of encapsulating various therapeutic agents, demonstrating improved stability, prolonged circulation times, and preferential accumulation in target tissues. Surface functionalization [...] Read more.

This research focuses on developing innovative nanoparticle-based drug delivery systems to enhance therapeutic efficacy while minimizing adverse effects. We engineered biocompatible polymeric nanoparticles capable of encapsulating various therapeutic agents, demonstrating improved stability, prolonged circulation times, and preferential accumulation in target tissues. Surface functionalization with targeting ligands achieved unprecedented specificity in drug delivery. Our nanoparticle formulations exhibited superior tumor accumulation in preclinical cancer models, enhancing therapeutic efficacy and reducing systemic toxicity. Additionally, we developed stimuli-responsive nanoparticles for precise spatiotemporal control over drug release. These advanced delivery systems promise to improve patient outcomes and advance personalized nanomedicine. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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5 pages, 796 KB

Open AccessProceeding Paper

Veterinary Blood Oxygen Detection

by Kimberly Mpala and Trudi-Heleen Joubert

Eng. Proc. 2025, 109(1), 20; https://doi.org/10.3390/engproc2025109020 - 28 Nov 2025

Viewed by 161

Abstract

A multimodal sensor was developed to record dissolved oxygen, L*a*b* colour, temperature, and pH. This work builds on an existing model that correlates blood oxygen saturation with L*a*b* colour values. An L*a*b* colour sensor was constructed from an RGB sensor and validated against [...] Read more.

A multimodal sensor was developed to record dissolved oxygen, L*a*b* colour, temperature, and pH. This work builds on an existing model that correlates blood oxygen saturation with L*a*b* colour values. An L*a*b* colour sensor was constructed from an RGB sensor and validated against a commercial colourimeter. Sensor performance was confirmed using reference colours. Dissolved oxygen was measured with a screen-printed electrode and an analogue-to-digital converter. The results highlight potential for future optical determination of oxygen saturation, combined with electrochemical measurement of oxygen partial pressure, and compensation for pH and temperature. Full article

(This article belongs to the Proceedings of Micro Manufacturing Convergence Conference)

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